Selected accession A0A9L0S961; ordinary UniProt record is TrEMBL and cites genome sequencing/submission rather than a gene-specific functional experiment. Human evidence is summarized in the paired human investigation. Sequence comparison records the exact target gaps and transfer limits. The targeted Europe PMC search found no decisive gene-specific horse functional assay warranting a separate horse Edison investigation; general omics/association hits were not counted as mechanistic validation.
The primary affinity-purification study identifies PP4R4 as a stable PP4c-specific partner and distinguishes it from PP2A/PP6 interactions and other PP4 regulatory complexes. PP4R4-associated activity toward fluorogenic substrate and gammaH2AX is lower than free PP4c and different from PP4R2/3-associated activity. This supports a regulatory subunit and an inhibitory effect in the tested assays, but does not establish that it inhibits all physiological PP4 substrates. It also does not establish blastocyst hatching. The selected horse sequence is nearly full-length and highly conserved, allowing stronger transfer of complex membership than a particular developmental phenotype.
Sources: PMID:18715871(https://pubmed.ncbi.nlm.nih.gov/18715871/).