WEE1

Review rationale: WEE1 is a conserved CDK-inhibitory kinase, but mammalian oocyte studies distinguish somatic WEE1 from WEE2/Wee1B. A mitotic checkpoint mechanism does not automatically establish regulation of meiosis I. Wee1B/WEE2 is the oocyte-specific MPF-inhibitory kinase that maintains prophase I arrest, but immunodetected wee1 is present in mouse oocyte nuclei during acquisition of meiotic competence (antibody specificity versus Wee1B not established), and Wee2 knockout mice retain fertility, so a somatic WEE1 contribution to meiosis I is neither shown nor excluded. No perturbation of somatic WEE1 in mammalian meiosis I was found in a PubMed search.

Review rationale: Human experiments place the soluble checkpoint kinase in the nucleus. Full-length horse sequence conservation (same PANTHER subfamily SF72 as human WEE1, which carries nucleoplasm from Reactome CDK1-phosphorylation reactions) supports nucleoplasmic activity. The horse gene carries only nucleus and nucleolus, so nucleoplasm is a novel, more specific location.

Review rationale: The characterized WEE1 checkpoint pool is nuclear, with additional cytoplasmic annotations. A PubMed search found membrane association for the paralog PKMYT1/Myt1 and cortical-node localization of fission-yeast Wee1, but no evidence establishing plasma-membrane recruitment of vertebrate WEE1. A soluble kinase can associate peripherally with a membrane, so absence of a transmembrane helix does not refute the prediction.

PARALOG OVERANNOTATION

Review rationale: The prediction assigns a WEE2/Wee1B oocyte process to the somatic WEE1 paralog. The selected horse F6TY09 sequence is a full-length WEE1 clade member, not the horse WEE2 protein, and the focused WEE1/WEE2 comparison places F6TY09 at ~90-95% identity to human and mouse WEE1 but only ~50% identity to WEE2 orthologs. The mouse experiment that supports female pronucleus assembly specifically showed Wee1B depletion blocking pronucleus formation while Wee1A-depleted oocytes activated correctly. Horse has a separate WEE2 entry, A0A9L0SIB9, and the WEE2 clade, not F6TY09, carries GO:0035038 across mammalian annotations. Later Wee2 knockout and possible-compensation evidence cautions against claiming that WEE2 is absolutely indispensable, but does not support transferring this WEE2-clade process back to somatic WEE1.

Review rationale: Protein phosphorylation follows directly from the conserved WEE1 tyrosine-kinase reaction. Mouse Wee1 has direct-assay evidence for protein phosphorylation, and the horse gene carries no phosphorylation process term, so the prediction is novel for this gene. It is correct but broad relative to the specific peptidyl-tyrosine phosphorylation of CDK1 Tyr15.

Review rationale: WEE1 catalyzes inhibitory CDK phosphorylation, which supports protein phosphorylation. A separate positive-regulation-of-phosphorylation process requires identifying the regulated reaction; the direct catalytic reaction alone does not establish that regulatory relationship, and effects on downstream CDK phosphorylation are inhibitory.

Review rationale: Mammalian studies identify WEE2/Wee1B as the oocyte-enriched paralog, whereas this horse sequence is WEE1. The broad female-meiosis term is not validated by conserved kinase activity alone. Redundancy and species-specific expression leave possible participation unresolved rather than proving absence. Immunodetected wee1 is present in mouse oocytes, and Wee2 knockout mice retain fertility, so neither indispensability of WEE2 nor absence of a WEE1 contribution is established.