Human brown fat inducible thioesterase variant 2 cellular localization and catalytic function.
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.
Department of Chemistry and Chemical Biology, University of New Mexico , Albuquerque, NM 87131, USA.
Danqi
D
Chen
John
J
Latham
Hong
H
Zhao
Marco
M
Bisoffi
Jeremiah
J
Farelli
Debra
D
Dunaway-Mariano
D000214:Acyl Coenzyme A / Q000378:metabolism; D000595:Amino Acid Sequence; D057809:HEK293 Cells; D006801:Humans; D008928:Mitochondria / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010170:Palmitoyl-CoA Hydrolase / Q000032:analysis* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D013869:Thiolester Hydrolases / Q000032:analysis* / Q000378:metabolism*; D000104:Acetyl-CoA Hydrolase
D000214:Acyl Coenzyme A; D010170:Palmitoyl-CoA Hydrolase; D013869:Thiolester Hydrolases; C499088:ACOT11 protein, human; C000594657:ACOT12 protein, human; D000104:Acetyl-CoA Hydrolase