phg2 (Q54QQ1, DDB_G0283699) — curation notes

Deep research status

2026-10-05: just deep-research-falcon DICDI phg2 --fallback perplexity-lite FAILED.
Falcon (Edison) returned 402 Payment Required; fallback provider perplexity not
available in this environment. No deep-research file was produced. Notes below are
built directly from the cached primary literature in publications/.

PMID	Topic	full_text_available
15194808	Gebbie 2004, isolation/phenotype of phg2	true, but cache only holds abstract + intro (results not cached)
16325504	Blanc 2005, N-terminal PI(4,5)P2-binding domain	false (abstract only)
16769729	Kortholt 2006, GbpD-Rap1-Phg2 pathway	false (abstract only)
16987957	Cherix 2006, Phg2-Adrm1 and development initiation	true
17371831	Jeon 2007, Rap1/Phg2 and myosin II	true
24587195	Vu 2014, Pyk3/Phg2 and STATc/PTP3	true

1387 aa; TKL-family Ser/Thr protein kinase domain 807-1072.
N-terminal PI(4,5)P2/PI(4)P-binding region 81-193 (membrane targeting).
Ras-association (RA/RBD) region in "core" region; Rap1-binding residues ~594-668,
Adrm1-binding residues 668-755 PMID:16987957.

Ser/Thr kinase: PMID:15194808.
Evidence for activity is indirect: PMID:17371831,
but PMID:17371831.
Phg2 is required (RA-domain dependent) for phosphorylation of cortical myosin II heavy
chain in a cytoskeletal kinase assay; MHCK-A overexpression bypasses this; the assay
cannot tell direct vs indirect PMID:17371831.
Phg2 required for PTP3 S747 phosphorylation PMID:24587195,
and binds PTP3 directly in pull-downs PMID:24587195.
No direct in vitro kinase assay on a defined substrate is reported -> candidate experiment.
Rap1-GTP binding via RA domain: PMID:16769729;
PMID:17371831.
GOA also has IPI for RasG and RasS from 15194808 (results not in cache; defer to curator).
PI(4,5)P2 binding: PMID:16325504; required for membrane recruitment and phagocytic function.
Adrm1 binding (Y2H + GST pulldown) PMID:16987957.

Plasma membrane / cortex, translocates to cortex on cAMP stimulation, enriched at
leading edge of chemotaxing cells PMID:17371831.
Localization independent of RA domain, PI3K and F-actin.
GFP-Nt-Phg2 (PIP2-binding domain probe) marks macropinosome/phagocytic cup membranes
until closure PMID:16325504.

Cell-substrate adhesion, phagocytosis (particle binding), motility, actin organization at
substrate interface PMID:15194808. Note discordant adhesion phenotypes between
backgrounds: DH1 phg2- less adhesive, KAx-3 phg2- more adhesive PMID:17371831.
Chemotaxis: phg2-null cells have broad leading edge, lateral pseudopodia, reduced F-actin
response, excess cortical myosin II PMID:17371831.
Negative regulator of nutrient-controlled initiation of development; cell autonomous;
kinase domain required; later development morphologically normal PMID:16987957.
STATc hyperosmotic response: Phg2 needed for full STATc phosphorylation and STATc target
gene induction, likely via inhibitory phosphorylation of PTP3 S747 PMID:24587195.

Kinase MF annotations accepted (deferring to IDA curators; domain is canonical).
protein binding IPIs: Ras/Rap -> MODIFY to small GTPase binding; PTP3 -> phosphatase binding;
Adrm1 -> REMOVE bare protein binding (interaction itself is real; no informative MF term).
ARBA "anatomical structure morphogenesis" removed: multicellular morphogenesis is normal
in phg2 mutants PMID:16987957.
Mitotic cytokinesis IMP (15194808): results section not cached, and the independent
phg2-null strain is "not multinucleated" PMID:17371831 -> UNDECIDED.