FAT1 (YBR041W; UniProt P38225) notes

• FATP/SLC27 family; very long-chain acyl-CoA synthetase PMID:9988704; fat1 accumulates C22-C26 PMID:9660783.
• No effect on long-chain ACS activity PMID:11330068, though overexpression adds oleoyl-CoA synthetase activity PMID:12601005.
• Long-chain fatty acid import, separable from VLCS activity PMID:15699031; complex with Faa1p/Faa4p PMID:12601005.
• Plasma membrane N(in)-C(in) topology, catalytic motifs cytoplasmic PMID:17679730.
• Peroxisomal VLCS activity PMID:11330068; inner peroxisomal membrane with Pxa1/Pxa2 PMID:22493507; ER/internal membranes PMID:9988704; lipid droplets [PMID:10515935; PMID:24868093].
• fat1 causes membrane saturation, Ole1 dysfunction, ER protein QC defect and UPR PMID:31746669 - indirect, over-annotation for "protein quality control".

Pathway-context observations

• YeastPathways assigns FAT1 to the EC 6.2.1.3 (long-chain) activation step; in peroxisomal beta-oxidation its role is VLCFA re-esterification (VLCS, GO:0031957). RCA GO:0004467 -> MODIFY GO:0031957. Cytosol RCA removed (integral membrane protein).