Human brown fat inducible thioesterase variant 2 cellular localization and catalytic function

Biochemistry. 2012 Sep 4;51(35):6990-9. doi: 10.1021/bi3008824. Epub 2012 Aug 23.

Abstract

The mammalian brown fat inducible thioesterase variant 2 (BFIT2), also known as ACOT11, is a multimodular protein containing two consecutive hotdog-fold domains and a C-terminal steroidogenic acute regulatory protein-related lipid transfer domain (StarD14). In this study, we demonstrate that the N-terminal region of human BFIT2 (hBFIT2) constitutes a mitochondrial location signal sequence, which undergoes mitochondrion-dependent posttranslational cleavage. The mature hBFIT2 is shown to be located in the mitochondrial matrix, whereas the paralog "cytoplasmic acetyl-CoA hydrolase" (CACH, also known as ACOT12) was found in the cytoplasm. In vitro activity analysis of full-length hBFIT2 isolated from stably transfected HEK293 cells demonstrates selective thioesterase activity directed toward long chain fatty acyl-CoA thioesters, thus distinguishing the catalytic function of BFIT2 from that of CACH. The results from a protein-lipid overlay test indicate that the hBFIT2 StarD14 domain binds phosphatidylinositol 4-phosphate.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acyl Coenzyme A / metabolism
  • Amino Acid Sequence
  • HEK293 Cells
  • Humans
  • Mitochondria / metabolism*
  • Models, Molecular
  • Molecular Sequence Data
  • Palmitoyl-CoA Hydrolase / analysis*
  • Palmitoyl-CoA Hydrolase / metabolism*
  • Protein Structure, Tertiary
  • Sequence Alignment
  • Thiolester Hydrolases / analysis*
  • Thiolester Hydrolases / metabolism*

Substances

  • Acyl Coenzyme A
  • ACOT11 protein, human
  • ACOT12 protein, human
  • Thiolester Hydrolases
  • Palmitoyl-CoA Hydrolase