PYK2 notes (P52489, YOR347C)

• Pyruvate kinase, EC 2.7.1.40 [UniProt:P52489 "Reaction=pyruvate + ATP = phosphoenolpyruvate + ADP + H(+);"]; Mg2+ and K+ cofactors by similarity only (ECO:0000250).
• Second, functional PK isoenzyme PMID:9139918; overexpression fully replaces Pyk1 PMID:9139918.
• FBP-insensitive and glucose-repressed PMID:9139918; PMID:9139918; proposed low-flux isoform PMID:9139918.
• Lower expression and specific activity than Pyk1 in pyk1 pyk2 background with ectopic expression PMID:21907146.
• Peripheral mitochondrial association of all glycolytic activities PMID:16962558 (abstract only; activity assays cannot separate Pyk1/Pyk2).
• Melatonin pull-down hit PMID:31708896 - note the paper's own naming confusion (calls it pyruvate kinase 1 but lists Pyk2p); weak affinity-capture evidence marked over-annotated.

Decisions: ACCEPT PK activity (all evidence), glycolysis, cytoplasm/cytosol; REMOVE bifid shunt (RCA mis-mapping from GLUCFERMEN-PWY); MODIFY obsolete GO:0061620 -> GO:0006096; MARK_AS_OVER_ANNOTATED monocarboxylic acid metabolic process (ARBA), melatonin binding; KEEP_AS_NON_CORE Mg/K binding, mitochondrion.