proliferation-associated protein 2G4; cell cycle protein p38-2G4 homolog; hG4-1; ErbB3-binding protein 1 (PA2G4, EBP1)

Function: - may play a role in a ERBB3-regulated signal transduction - seems be involved in growth regulation - corepressor of the androgen receptor (AR) - regulated by the ERBB3 ligand neuregulin-1/heregulin (HRG) - inhibits transcription of some E2F1-regulated promoters, probably by recruiting histone acetylase (HAT) activity - binds RNA - associates with 28S, 18S & 5.8S mature rRNAs, several rRNA precursors & probably U3 small nucleolar RNA - may be involved in regulation of intermediate & late steps of rRNA processing - may be involved in ribosome assembly - phosphorylated on Ser & Thr - phosphorylation is enhanced by HRG treatment - basal phosphorylation is PKC-dependent - HRG-induced phosphorylation is predominantly PKC-independent - interacts with the cytoplasmic domain of non-phosphorylated ERBB3; the interaction requires PKC activity - interacts with AR - treatment with HRG leads to dissociation from ERBB3 & increases association with AR - interacts with NCL/nucleolin - component of a ribonucleoprotein complex containing at least PA2G4, NCL, TOP1, PABPC2, RPLP0, acetylated histone H1 (HIST1H1A or H1F1), histone H1 2/4, RPL4, RPL8, RPL15, RPL18, RPL18A, RPL21, RPL11, RPL12, RPL28, RPL27, RPLP2 & RPL24 - interacts with HDAC2 - interacts with RB1 - the interaction is enhanced upon PA2G4 dephosphorylation Structure: belongs to the peptidase M24 family Compartment: - cytoplasm. nucleus, nucleolus - tranlocates to the nucleus upon treatment with HRG Expression: - expressed in several cell lines tested, including primary & transformed cell lines Pathology: - mediates cap-independent translation of specific viral IRESs (internal ribosomal entry site) (putative) Notes: - does not contain metal cofactor - does not have aminopeptidase activity

General

nuclear protein phosphoprotein

Properties

SIZE: entity length = 394 aa MW = 44 kD COMPARTMENT: cytoplasm cell nucleus MOTIF: nucleolar localization {2-48} acetylation site SITE: N-TERMINUS EFFECTOR-BOUND: acetyl Ser phosphorylation site {S2} Thr phosphorylation site {T11} binding site SITE: 46-54 FOR-BINDING-OF: ribonucleic acid Necessary for nucleolar localization {301-394} MOTIF: RNA interaction {361-375} Ser phosphorylation site {S361} Thr phosphorylation site {T366} Ser phosphorylation site {S383} Thr phosphorylation site {T386}

Database Correlations

OMIM 602145 UniProt Q9UQ80 Pfam PF00557 Entrez Gene 5036 Kegg hsa:5036

References

UniProt :accession Q9UQ80