Selected horse accession: A0A9L0TTC1. Source: ProtNLM2 API snapshot 2026-09-08, frozen in horse40-predictions.csv.
Esterifies acyl-group from acyl-ACP to the sn-1 position of glycerol-3-phosphate, an essential step in glycerolipids biosynthesis such as triglycerides, phosphatidic acids and lysophosphatidic acids
PLI. The experimentally characterized mammalian mitochondrial GPAT1 reaction uses fatty acyl-CoA; the curated human reaction and structural substrate-binding information identify the CoA-linked donor. Acyl-ACP donor usage fits bacterial/other glycerolipid acyltransferase contexts and is not established for GPAM. Conserved horse GPAM architecture and 94.2% identity favor transfer of the mammalian substrate class, not the alternate donor. PMID:36522428(https://pubmed.ncbi.nlm.nih.gov/36522428/); DOI:10.1038/s41594-022-00884-7.
UNC for this selected sequence. The chemical position and biosynthetic role fit GPAT1, whose product is lysophosphatidic acid and feeds phosphatidic acid and triacylglycerol biosynthesis. These claims are not novel for the horse gene: GOA already carries glycerol-3-phosphate O-acyltransferase activity (GO:0004366) and phospholipid biosynthetic process (GO:0008654) for horse GPAM, and the canonical product A0A9L0TCA8 also carries triglyceride biosynthetic process (GO:0019432). A0A9L0TTC1 is an alternative isoform that lacks human residues 370–407 (gene-model comparison). The segment is conserved in human, mouse, rat and the canonical horse product, and forms resolved helices and a strand in the catalytic domain of the human cryo-EM structure. The HXXXXD catalytic motif and the six CoA-binding residues are retained, so no known catalytic residue is missing. Whether the shortened protein folds and acylates glycerol-3-phosphate has not been tested, so activity of this exact sequence, and its contribution to glycerolipid biosynthesis, are unresolved. PMID:36522428(https://pubmed.ncbi.nlm.nih.gov/36522428/); DOI:10.1038/s41594-022-00884-7.
Human–horse sequence comparison records coverage, gaps and architecture caveats. Human experimental results support transfer where the relevant features are conserved; ARBA assertions and generated gene-review prose are not used as biological evidence. The human reference sequence and current horse sequence are not known to be the exact prediction-time inputs. Claim assessments are kept separate because a partly correct paragraph should not receive an undifferentiated verdict.