Basic leucine zipper (bZIP) domain of bZIP transcription factors: a DNA-binding and dimerization domain; Basic leucine zipper (bZIP) factors comprise one of the most important classes of enhancer-type transcription factors. They act in networks of homo and heterodimers in the regulation of a diverse set of cellular processes including cell survival, learning and memory, lipid metabolism, and cancer progression, among others. They also play important roles in responses to stimuli or stress signals such as cytokines, genotoxic agents, or physiological stresses. 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 1254064656  28 NRVAAQRSRQKHTSKADALH-QHESLEKQNHALRKEIQALQTELAGW 73
Cdd:cd14701    11 NRDAAQRSRQKQTEKADKLHeESESLERANAALRKEIKDLTEELKYL 57

Basic leucine zipper (bZIP) domain of BATF proteins: a DNA-binding and dimerization domain; Basic leucine zipper (bZIP) transcription factor ATF-like (BATF or SFA2), BATF2 (or SARI) and BATF3 form heterodimers with Jun proteins. They function as inhibitors of AP-1-driven transcription. Unlike most bZIP transcription factors that contain additional domains, BATF and BATF3 contain only the the bZIP DNA-binding and dimerization domain. BATF2 contains an additional C-terminal domain of unknown function. BATF:Jun hetrodimers preferentially bind to TPA response elements (TREs) with the consensus sequence TGA(C/G)TCA, and can also bind to a TGACGTCA cyclic AMP response element (CRE). In addition to negative regulation, BATF proteins also show positive transcriptional activities in the development of classical dendritic cells and T helper cell subsets, and in antibody production. 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 1254064656  28 NRVAAQRSRQKHTSKADALH-QHESLEKQNHALRKEIQALQTELAGW 73
Cdd:cd14701    11 NRDAAQRSRQKQTEKADKLHeESESLERANAALRKEIKDLTEELKYL 57

Basic region leucine zipper;

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|...
gi 1254064656  28 NRVAAQRSRQKHTSKADAL-HQHESLEKQNHALRKEIQALQTE 69
Cdd:pfam07716   9 NNEAAKRSREKKKQKEEELeERVKELERENAQLRQKVEQLEKE 51

Basic leucine zipper (bZIP) domain of BATF proteins: a DNA-binding and dimerization domain; Basic leucine zipper (bZIP) transcription factor ATF-like (BATF or SFA2), BATF2 (or SARI) and BATF3 form heterodimers with Jun proteins. They function as inhibitors of AP-1-driven transcription. Unlike most bZIP transcription factors that contain additional domains, BATF and BATF3 contain only the the bZIP DNA-binding and dimerization domain. BATF2 contains an additional C-terminal domain of unknown function. BATF:Jun hetrodimers preferentially bind to TPA response elements (TREs) with the consensus sequence TGA(C/G)TCA, and can also bind to a TGACGTCA cyclic AMP response element (CRE). In addition to negative regulation, BATF proteins also show positive transcriptional activities in the development of classical dendritic cells and T helper cell subsets, and in antibody production. 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 1254064656  28 NRVAAQRSRQKHTSKADALH-QHESLEKQNHALRKEIQALQTELAGW 73
Cdd:cd14701    11 NRDAAQRSRQKQTEKADKLHeESESLERANAALRKEIKDLTEELKYL 57

basic region leucin zipper;

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*
gi 1254064656   28 NRVAAQRSRQKHTSKADAL-HQHESLEKQNHALRKEIQALQTELA 71
Cdd:smart00338  13 NREAARRSRERKKAEIEELeRKVEQLEAENERLKKEIERLRRELE 57

Basic leucine zipper (bZIP) domain of Activating Transcription Factor-2 (ATF-2) and similar proteins: a DNA-binding and dimerization domain; ATF-2 is a sequence-specific DNA-binding protein that belongs to the Basic leucine zipper (bZIP) family of transcription factors. In response to stress, it activates a variety of genes including cyclin A, cyclin D, and c-Jun. ATF-2 also plays a role in the DNA damage response that is independent of its transcriptional activity. 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 1254064656  28 NRVAAQRSRQKHTSKADAL-HQHESLEKQNHALRKEIQALQTELA 71
Cdd:cd14687     9 NRIAASKCRQRKKQWVQQLeEKVRKLESENKALKAEVDKLREEVL 53

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
                  ....*....|....*....|....*....|....*....|
gi 1254064656  28 NRVAAQRSRQKHTSKADALH-QHESLEKQNHALRKEIQAL 66
Cdd:cd14691    11 NRVAAQTARDRKKARMDELEeRVRELEEENQKLRAENESL 50

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
                  ....*....|....*....|....*....|....*....|...
gi 1254064656  28 NRVAAQRSRQKHTSKADALHQH-ESLEKQNHALRKEIQALQTE 69
Cdd:cd14721     9 NKLAAAKCRQRRVDLTNTLQAEtEQLEDEKSSLQNEIANLQKQ 51

Basic leucine zipper (bZIP) domain of Activating Transcription Factor-3 (ATF-3) and similar proteins: a DNA-binding and dimerization domain; ATF-3 is a Basic leucine zipper (bZIP) transcription factor that is induced by various stress signals such as cytokines, genetoxic agents, or physiological stresses. It is implicated in cancer and host defense against pathogens. It negatively regulates the transcription of pro-inflammatory cytokines and is critical in preventing acute inflammatory syndromes. Mice deficient with ATF3 display increased susceptibility to endotoxic shock induced death. ATF3 dimerizes with Jun and other ATF proteins; the heterodimers function either as activators or repressors depending on the promoter context. 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 1254064656  28 NRVAAQRSRQKHTSKADALHQH-ESLEKQNHALRKEIQALQTE 69
Cdd:cd14722     9 NKVAAAKCRNKKKERTDCLQKEsEKLETQNAELKRQIEELKNE 51

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
                  ....*....|....*....|....*....|....*....|....*...
gi 1254064656  28 NRVAAQRSRQKhtsKADALhqhESLEKQNHALRKEIQALQTELAGWGR 75
Cdd:cd12193    10 NTLAARRSRAR---KLEEM---EELEKRVEELEAENEELKTRAEVLEA 51

Basic leucine zipper (bZIP) domain of CCAAT/enhancer-binding protein (CEBP) and similar proteins: a DNA-binding and dimerization domain; 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 1254064656  28 NRVAAQRSRQKhtSKADALHQHE---SLEKQNHALRKEIQALQTELA 71
Cdd:cd14693    12 NNIAVRKSREK--AKQRQLETQQkvqELRKENERLQKRVELLTKELS 56

Homeobox associated leucine zipper;

                          10        20
                  ....*....|....*....|....
gi 1254064656  44 DAL-HQHESLEKQNHALRKEIQAL 66
Cdd:pfam02183  15 DALkSDFDSLKKENQKLQAELQEL 38