4n8m | pdb_00004n8m
Structural polymorphism in the N-terminal oligomerization domain of NPM1
Structural highlights
FunctionNPM_MOUSE Involved in diverse cellular processes such as ribosome biogenesis, centrosome duplication, protein chaperoning, histone assembly, cell proliferation, and regulation of tumor suppressors p53/TP53 and ARF. Binds ribosome presumably to drive ribosome nuclear export. Acts as a chaperonin for the core histones H3, H2B and H4. Stimulates APEX1 endonuclease activity on apurinic/apyrimidinic (AP) double-stranded DNA but inhibits APEX1 endonuclease activity on AP single-stranded RNA. May exert a control of APEX1 endonuclease activity within nucleoli devoted to repair AP on rDNA and the removal of oxidized rRNA molecules (By similarity). Associated with nucleolar ribonucleoprotein structures and bind single-stranded nucleic acids. In concert with BRCA2, regulates centrosome duplication. Regulates centriole duplication: phosphorylation by PLK2 is able to trigger centriole replication (By similarity). Negatively regulates the activation of EIF2AK2/PKR and suppresses apoptosis through inhibition of EIF2AK2/PKR autophosphorylation (By similarity). Publication Abstract from PubMedNucleophosmin (NPM1) is a multifunctional phospho-protein with critical roles in ribosome biogenesis, tumor suppression, and nucleolar stress response. Here we show that the N-terminal oligomerization domain of NPM1 (Npm-N) exhibits structural polymorphism by populating conformational states ranging from a highly ordered, folded pentamer to a highly disordered monomer. The monomer-pentamer equilibrium is modulated by posttranslational modification and protein binding. Phosphorylation drives the equilibrium in favor of monomeric forms, and this effect can be reversed by Npm-N binding to its interaction partners. We have identified a short, arginine-rich linear motif in NPM1 binding partners that mediates Npm-N oligomerization. We propose that the diverse functional repertoire associated with NPM1 is controlled through a regulated unfolding mechanism signaled through posttranslational modifications and intermolecular interactions. Structural polymorphism in the N-terminal oligomerization domain of NPM1.,Mitrea DM, Grace CR, Buljan M, Yun MK, Pytel NJ, Satumba J, Nourse A, Park CG, Madan Babu M, White SW, Kriwacki RW Proc Natl Acad Sci U S A. 2014 Mar 25;111(12):4466-71. doi:, 10.1073/pnas.1321007111. Epub 2014 Mar 10. PMID:24616519[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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