Selected horse accession: A0A9L0S5Z5. Source: ProtNLM2 API snapshot 2026-09-08, frozen in horse40-predictions.csv.
Component of the ribosome-associated complex (RAC), a complex involved in folding or maintaining nascent polypeptides in a folding-competent state. In the RAC complex, binds to the nascent polypeptide chain, while DNAJC2 stimulates its ATPase activity
PLI. Primary work identifies the human RAC pair as Mpp11 and Hsp70L1, while Apg2/HSPA4 experiments establish nucleotide exchange on Hsc70 in a chaperone/disaggregase system. Generic Hsp70-family similarity does not place HSPA4 in RAC. The selected horse protein is a near-identical HSPA4 homolog with its ATPase region retained and an internal C-terminal-region deletion; it is not thereby the RAC Hsp70 paralog. PMID:36604744(https://pubmed.ncbi.nlm.nih.gov/36604744/).
Supported at broad level. Apg2/HSPA4 supports Hsc70-dependent aggregate reactivation as a nucleotide-exchange factor. This validates broad chaperone biology, not the particular ribosome-bound mechanism or direct nascent-chain-binding role asserted by the paragraph. PMID:30521813(https://pubmed.ncbi.nlm.nih.gov/30521813/); DOI:10.1016/j.jmb.2018.11.026.
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.