title: Nucleolar protein CSIG is required for p33ING1 function in UV-induced apoptosis.
abstract: Cellular senescence-inhibited gene (CSIG) protein, a nucleolar protein with a ribosomal L1 domain in its N-terminus, can exert non-ribosomal functions to regulate biological processes, such as cellular senescence. Here, we describe a previously unknown function for CSIG: promotion of apoptosis in response to ultraviolet (UV) irradiation-induced CSIG upregulation. We identified p33ING1 as a binding partner that interacts with CSIG. After UV irradiation, p33ING1 increases its protein expression, translocates into the nucleolus and binds CSIG. p33ING1 requires its nucleolar targeting sequence region to interact with CSIG and enhance CSIG protein stability, which is essential for activation of downstream effectors, Bcl-2-associated X protein, to promote apoptosis. Thus, our data imply that p33ING1-CSIG axis functions as a novel pro-apoptotic regulator in response to DNA damage.
authors.affiliation: Research Center on Aging, Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing, People's Republic of China.
authors.forename: N
authors.initials: N
authors.lastname: Li
authors.forename: G
authors.initials: G
authors.lastname: Zhao
authors.forename: T
authors.initials: T
authors.lastname: Chen
authors.forename: L
authors.initials: L
authors.lastname: Xue
authors.forename: L
authors.initials: L
authors.lastname: Ma
authors.forename: J
authors.initials: J
authors.lastname: Niu
authors.forename: T
authors.initials: T
authors.lastname: Tong
mesh_terms: D017209:Apoptosis / Q000235:genetics / Q000528:radiation effects*; D001665:Binding Sites; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D004249:DNA Damage / Q000235:genetics / Q000528:radiation effects; D015870:Gene Expression / Q000528:radiation effects; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D000076023:Inhibitor of Growth Protein 1; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011257:Pregnancy Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D021381:Protein Transport / Q000235:genetics / Q000528:radiation effects; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics* / Q000528:radiation effects; D014162:Transfection; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D014466:Ultraviolet Rays; D015854:Up-Regulation / Q000528:radiation effects; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: C501503:ING1 protein, human; D000076023:Inhibitor of Growth Protein 1; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D011257:Pregnancy Proteins; C117409:RSL1D1 protein, human; D012269:Ribosomal Proteins; D025521:Tumor Suppressor Proteins; D051028:bcl-2-Associated X Protein