Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein beta (CEBPB): a DNA-binding and dimerization domain; CEBPB is a key regulator of metabolism, adipocyte differentiation, myogenesis, and macrophage activation. It is expressed as three distinct isoforms from an intronless gene through alternative translation initiation: CEBPB1 (or liver-enriched activator protein 1, LAP1); CEBPB2 (OR LAP2); and CEBPB3 (or liver-enriched inhibitory protein, LIP). LAP1/2 function as transcriptional activators while LIP is a repressor due to its lack of a transactivation domain. The relative expression of LAP and LIP has effects on inflammation, ER stress, and insulin resistance. CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate many cellular processes. There are six CEBP proteins in mammalian cells including CEBPA (alpha), CEBPB (beta), CEBPG (gamma), CEBPD (delta), and CEBPE (epsilon), which all contain highly conserved bZIP domains at their C-termini and variations at their N-terminal regions. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 551895085 241 KKTVDKHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRNLFKQL 311
Cdd:cd14712    1 KKTVDKHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRNLFKQL 71

Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein beta (CEBPB): a DNA-binding and dimerization domain; CEBPB is a key regulator of metabolism, adipocyte differentiation, myogenesis, and macrophage activation. It is expressed as three distinct isoforms from an intronless gene through alternative translation initiation: CEBPB1 (or liver-enriched activator protein 1, LAP1); CEBPB2 (OR LAP2); and CEBPB3 (or liver-enriched inhibitory protein, LIP). LAP1/2 function as transcriptional activators while LIP is a repressor due to its lack of a transactivation domain. The relative expression of LAP and LIP has effects on inflammation, ER stress, and insulin resistance. CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate many cellular processes. There are six CEBP proteins in mammalian cells including CEBPA (alpha), CEBPB (beta), CEBPG (gamma), CEBPD (delta), and CEBPE (epsilon), which all contain highly conserved bZIP domains at their C-termini and variations at their N-terminal regions. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 551895085 241 KKTVDKHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRNLFKQL 311
Cdd:cd14712    1 KKTVDKHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRNLFKQL 71

basic region leucin zipper;

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 551895085   246 KHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRNLFKQ 310
Cdd:smart00338   1 EEDEKRRRRRERNREAARRSRERKKAEIEELERKVEQLEAENERLKKEIERLRRELEKLKSELEE 65

Prefoldin, chaperonin cofactor [Posttranslational modification, protein turnover, chaperones];

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 551895085 239 KAKKTVDKHSDEYKIRRERNNIAVRKSRDKA------KMRNLETQHKVLElTAEnERLQKKVEQLSREL 301
Cdd:COG1382   42 KALEELEKLPDDAEVYKSVGNLLVKTDKEEVikeleeKKETLELRLKTLE-KQE-ERLQKQLEELQEKL 108

Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein beta (CEBPB): a DNA-binding and dimerization domain; CEBPB is a key regulator of metabolism, adipocyte differentiation, myogenesis, and macrophage activation. It is expressed as three distinct isoforms from an intronless gene through alternative translation initiation: CEBPB1 (or liver-enriched activator protein 1, LAP1); CEBPB2 (OR LAP2); and CEBPB3 (or liver-enriched inhibitory protein, LIP). LAP1/2 function as transcriptional activators while LIP is a repressor due to its lack of a transactivation domain. The relative expression of LAP and LIP has effects on inflammation, ER stress, and insulin resistance. CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate many cellular processes. There are six CEBP proteins in mammalian cells including CEBPA (alpha), CEBPB (beta), CEBPG (gamma), CEBPD (delta), and CEBPE (epsilon), which all contain highly conserved bZIP domains at their C-termini and variations at their N-terminal regions. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 551895085 241 KKTVDKHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRNLFKQL 311
Cdd:cd14712    1 KKTVDKHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRNLFKQL 71

Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein alpha (CEBPA): a DNA-binding and dimerization domain; CEPBA is a critical regulator of myeloid development; it directs granulocyte and monocyte differentiation. It is highly expressed in early myeloid progenitors and is found mutated in over half of patients with acute myeloid leukemia (AML). It is also a key regulator in energy homeostasis; mice deficient of CEBPA show abnormalities in glycogen/lipid synthesis and storage. CEPBA is the longest CEBP protein containing two transactivation domains at the N-terminus followed by a regulatory domain, a bZIP domain, and C-terminal tail. CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate many cellular processes. There are six CEBP proteins in mammalian cells including CEBPA (alpha), CEBPB (beta), CEBPG (gamma), CEBPD (delta), and CEBPE (epsilon), which all contain highly conserved bZIP domains at their C-termini and variations at their N-terminal regions. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 551895085 246 KHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLR 305
Cdd:cd14711    1 KNSNEYRVRRERNNIAVRKSRDKAKQRNVETQQKVLELTSDNDRLRKRVEQLSRELETLR 60

Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein epsilon (CEBPE): a DNA-binding and dimerization domain; CEBPE is a critical regulator of terminal granulocyte differentiation or granulopoiesis. It is expressed only in myeloid cells. Mice deficient with CEBPE are normal at birth and fertile, but they do not produce normal neutrophils or eosinophils, and show impaired inflammatory and bacteriocidal responses. Functional loss of CEBPE causes the rare congenital disorder, Neutrophil-specific granule deficiency (SGD), which is characterized by patients' neutrophils with atypical nuclear morphology, abnormal migration and bactericidal activity, and the lack of specific granules. Patients with SGD suffer from severe and frequent bacterial infections. CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate many cellular processes. There are six CEBP proteins in mammalian cells including CEBPA (alpha), CEBPB (beta), CEBPG (gamma), CEBPD (delta), and CEBPE (epsilon), which all contain highly conserved bZIP domains at their C-termini and variations at their N-terminal regions. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 551895085 246 KHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRN 306
Cdd:cd14715    1 KDSLEYRLRRERNNIAVRKSRDKAKRRVLETQQRMLEYMAENERLRSRVEQLTQELDTLRD 61

Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein (CEBP)-like proteins: a DNA-binding and dimerization domain; This group is an uncharacterized subfamily of CEBP-like proteins. CEBPs (or C/EBPs) are Basic leucine zipper (bZIP) transcription factors that regulate the cell cycle, differentiation, growth, survival, energy metabolism, innate and adaptive immunity, and inflammation, among others. They are also associated with cancer and viral disease. There are six CEBP proteins in mammalian cells including CEBPA (alpha), CEBPB (beta), CEBPG (gamma), CEBPD (delta), and CEBPE (epsilon), which all contain highly conserved bZIP domains at their C-termini and variations at their N-terminal regions. Each possesses unique properties to regulate cell type-specific growth and differentiation. The sixth isoform, CEBPZ (zeta), lacks an intact DNA-binding domain and is excluded from this subfamily. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|..
gi 551895085 248 SDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENER 289
Cdd:cd14716    2 SDEYRKRRERNNIAVRKSRDKAKLRNLETQQKLIELHNETKT 43

basic region leucin zipper;

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 551895085   246 KHSDEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRNLFKQ 310
Cdd:smart00338   1 EEDEKRRRRRERNREAARRSRERKKAEIEELERKVEQLEAENERLKKEIERLRRELEKLKSELEE 65

Basic leucine zipper (bZIP) domain of Hepatic leukemia factor (HLF) and similar proteins: a DNA-binding and dimerization domain; HLF, also called vitellogenin gene-binding protein (VBP) in birds, is a circadian clock-controlled Basic leucine zipper (bZIP) transcription factor which is a direct transcriptional target of CLOCK/BMAL1. It is implicated, together with bZIPs DBP and TEF, in the regulation of genes involved in the metabolism of endobiotic and xenobiotic agents. Triple knockout mice display signs of early aging and suffer premature death, likely due to impaired defense against xenobiotic stress. A leukemogenic translocation results in the chimeric fusion protein E2A-HLF that results in a rare form of pro-B-cell acute lymphoblastic leukemia (ALL). bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 551895085 249 DEYKIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRN 306
Cdd:cd14695    3 DKYWERRRKNNLAAKRSRDARRLKENQIAIRAAFLEKENAALRAEIAKLKKELEDLRK 60

Basic leucine zipper (bZIP) domain of blue light (BL) receptor aureochrome (AUREO) and similar bZIP domains; AUREO is a BL-activated transcription factor specific to phototrophic stramenopiles. It has a bZIP and a BL-sensing light-oxygen voltage (LOV) domain. It has been shown to mediate BL-induced branching and regulate the development of the sex organ in Vaucheria frigida. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription. This subgroup also includes the Epstein-Barr virus (EBV) immediate-early transcription factor ZEBRA (BZLF1, Zta, Z, EB1). ZEBRA exhibits a variant of the bZIP fold, it has a unique dimer interface and a substantial hydrophobic pocket; it has a C-terminal moiety which stabilizes the coiled coil involved in dimer formation. ZEBRA functions to trigger the switch of EBV's biphasic infection cycle from latent to lytic infection. It activates the promoters of EBV lytic genes by binding ZEBRA response elements (ZREs) and inducing a cascade of expression of over 50 viral genes. It also down regulates latency-associated promoters, is an essential replication factor, induces host cell cycle arrest, and alters cellular immune responses and transcription factor activity.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 551895085 252 KIRRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELS 302
Cdd:cd14809    2 ERRRERNREHARKTRLRKKAYLESLKEQVAALQAENQRLRQQIRQAAPASA 52

Basic leucine zipper (bZIP) domain of General control protein GCN4: a DNA-binding and dimerization domain; GCN4 was identified in Saccharomyces cerevisiae from mutations in a deficiency in activation with the general amino acid control pathway. GCN4 encodes a trans-activator of amino acid biosynthetic genes containing 2 acidic activation domains and a C-terminal bZIP domain. In amino acid-deprived cells, GCN4 is up-regulated leading to transcriptional activation of genes encoding amino acid biosynthetic enzymes. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 551895085 249 DEYKIRRERNNIAVRKSRDK--AKMRNLETQhkVLELTAENERLQKKVEQLSRELS 302
Cdd:cd12193    1 DPVAAKRARNTLAARRSRARklEEMEELEKR--VEELEAENEELKTRAEVLEAEAR 54

Basic leucine zipper (bZIP) domain of Fungal Zip1-like transcription factors: a DNA-binding and dimerization domain; This subfamily is composed of fungal bZIP transcription factors including Schizosaccharomyces pombe Zip1, Saccharomyces cerevisiae Methionine-requiring protein 28 (Met28p), and Neurospora crassa cys-3, among others. Zip1 is required for the production of key proteins involved in sulfur metabolism and also plays a role in cadmium response. Met28p acts as a cofactor of Met4p, a transcriptional activator of the sulfur metabolic network; it stabilizes DNA:Met4 complexes. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*..
gi 551895085 254 RRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRE 300
Cdd:cd14705    4 KRRRNTAASARFRAKKKQREQELEEKLKELEERIKELERRLDELESE 50

Basic leucine zipper (bZIP) domain of X-box binding protein 1 (XBP1) and similar proteins: a DNA-binding and dimerization domain; XBP1, a member of the Basic leucine zipper (bZIP) family, is the key transcription factor that orchestrates the unfolded protein response (UPR). It is the most conserved component of the UPR and is critical for cell fate determination in response to ER stress. The inositol-requiring enzyme 1 (IRE1)-XBP1 pathway is one of the three major sensors at the ER membrane that initiates the UPR upon activation. IRE1, a type I transmembrane protein kinase and endoribonuclease, oligomerizes upon ER stress leading to its increased activity. It splices the XBP1 mRNA, producing a variant that translocates to the nucleus and activates its target genes, which are involved in protein folding, degradation, and trafficking. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 551895085 254 RRERNNIAVRKSRD--KAKMRNLETQhkVLELTAENERLQKKVEQLSRELSTLR 305
Cdd:cd14691    7 RKLKNRVAAQTARDrkKARMDELEER--VRELEEENQKLRAENESLRARNEDLL 58

bZIP transcription factor; The Pfam entry includes the basic region and the leucine zipper region.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 551895085  254 RRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLR 305
Cdd:pfam00170   5 RKQSNREAARRSRQRKQAYIEELERRVKALEGENKTLRSELEELKKEVEKLK 56

Basic leucine zipper (bZIP) domain of Jun proteins and similar proteins: a DNA-binding and dimerization domain; Jun is a member of the activator protein-1 (AP-1) complex, which is mainly composed of Basic leucine zipper (bZIP) dimers of the Jun and Fos families, and to a lesser extent, the activating transcription factor (ATF) and musculoaponeurotic fibrosarcoma (Maf) families. The broad combinatorial possibilities for various dimers determine binding specificity, affinity, and the spectrum of regulated genes. The AP-1 complex is implicated in many cell functions including proliferation, apoptosis, survival, migration, tumorigenesis, and morphogenesis, among others. There are three Jun proteins: c-Jun, JunB, and JunD. c-Jun is the most potent transcriptional activator of the AP-1 proteins. Both c-Jun and JunB are essential during development; deletion of either results in embryonic lethality in mice. c-Jun is essential in hepatogenesis and liver erythropoiesis, while JunB is required in vasculogenesis and angiogenesis in extraembryonic tissues. While JunD is dispensable in embryonic development, it is involved in transcription regulation of target genes that help cells to cope with environmental signals. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 551895085 254 RRERNNIAVRKSRDKAKMRNLETQHKVLELTAENERLQKKVEQLSRELSTLRN 306
Cdd:cd14696    5 KRARNRIAASKCRKRKLERIARLEDKVKELKNQNSELTSTASLLREQVCQLKQ 57

Basic leucine zipper (bZIP) domain of CREBZF/Zhangfei transcription factor and similar proteins: a DNA-binding and dimerization domain; CREBZF (also called Zhangfei, ZF, LAZip, or SMILE) is a neuronal bZIP transcription factor that is involved in the infection cycle of herpes simplex virus (HSV) and related cellular processes. It suppresses the ability of the HSV transactivator VP16 to initiate the viral replicative cycle. CREBZF has also been implicated in the regulation of the human nerve growth factor receptor trkA and the tumor suppressor p53. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 551895085 254 RRERNNIAVRKSRDKAK--MRNLETqhKVLELTAENERLQKKVEQLSRELSTL 304
Cdd:cd14706    4 VMSKNAIAARENRLKKKeyVENLEK--SVDKLKSENKELKKANKKLQKLVEEL 54

Basic leucine zipper (bZIP) domain of the oncogene Fos (Fos): a DNA-binding and dimerization domain; Fos proteins are members of the activator protein-1 (AP-1) complex, which is mainly composed of Basic leucine zipper (bZIP) dimers of the Jun and Fos families, and to a lesser extent, the activating transcription factor (ATF) and musculoaponeurotic fibrosarcoma (Maf) families. The broad combinatorial possibilities for various dimers determine binding specificity, affinity, and the spectrum of regulated genes. The AP-1 complex is implicated in many cell functions including proliferation, apoptosis, survival, migration, tumorigenesis, and morphogenesis, among others. There are four Fos proteins: c-Fos, FosB, Fos-related antigen 1 (Fra-1), and Fra-2. In addition, FosB also exists as smaller splice variants FosB2 and deltaFosB2. They all contain an N-terminal region and a bZIP domain. c-Fos and FosB also contain a C-terminal transactivation domain which is absent in Fra-1/2 and the smaller FosB variants. Fos proteins can only heterodimerize with Jun and other AP-1 proteins, but cannot homodimerize. Fos:Jun heterodimers are more stable and can bind DNA with more affinity that Jun:Jun homodimers. Fos proteins can enhance the trans-activating and transforming properties of Jun proteins. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 551895085 252 KIRRERNNIAVRKSRDKakmRNLETQhkvlELTAENERLQKKVEQLSRELSTLRNLFKQLpEPLLAS 318
Cdd:cd14721    3 RVRRERNKLAAAKCRQR---RVDLTN----TLQAETEQLEDEKSSLQNEIANLQKQKEQL-EFLLAA 61

Basic leucine zipper (bZIP) domain of Yeast Activator Protein (YAP) and similar proteins: a DNA-binding and dimerization domain; This subfamily is composed predominantly of AP-1-like transcription factors including Saccharomyces cerevisiae YAPs, Schizosaccharomyces pombe PAP1, and similar proteins. Members of this subfamily belong to the Basic leucine zipper (bZIP) family of transcription factors. The YAP subfamily is composed of eight members (YAP1-8) which may all be involved in stress responses. YAP1 is the major oxidative stress regulator and is also involved in iron metabolism (like YAP5) and detoxification of arsenic (like YAP8). YAP2 is involved in cadmium stress responses while YAP4 and YAP6 play roles in osmotic stress. bZIP factors act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes. The bZIP structural motif contains a basic region and a leucine zipper, composed of alpha helices with leucine residues 7 amino acids apart, which stabilize dimerization with a parallel leucine zipper domain. Dimerization of leucine zippers creates a pair of the adjacent basic regions that bind DNA and undergo conformational change. Dimerization occurs in a specific and predictable manner resulting in hundreds of dimers having unique effects on transcription.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 551895085 254 RRERNNIAVRKSRD--KAKMRNLEtqHKVLELTAENERLQKKVEQLSRELSTLRNLFKQL 311
Cdd:cd14688    6 RRAQNREAQRAFRErkKERIKELE--QRVAELEEELAELEEELQELRAELRELESELQSL 63