title: HSP27 phosphorylation modulates TRAIL-induced activation of Src-Akt/ERK signaling through interaction with β-arrestin2.
abstract: Heat shock protein 27 (HSP27) regulates critical cellular functions such as development, differentiation, cell growth and apoptosis. A variety of stimuli induce the phosphorylation of HSP27, which affects its cellular functions. However, most previous studies focused on the role of HSP27 protein itself in apoptosis, the particular role of its phosphorylation state in signaling transduction remains largely unclear. In the present study, we reported that HSP27 phosphorylation modulated TRAIL-triggered pro-survival signaling transduction. In HeLa cells, suppression of HSP27 phosphorylation by specific inhibitor KRIBB3 or MAPKAPK2 (MK2) knockdown and by overexpression of non-phosphorylatable HSP27(3A) mutant demonstrated that hindered HSP27 phosphorylation enhanced the TRAIL-induced apoptosis. In addition, reduced HSP27 phosphorylation by KRIBB3 treatment or MK2 knockdown attenuated the TRAIL-induced activation of Akt and ERK survival signaling through suppressing the phosphorylation of Src. By overexpression of HSP27(15A) or HSP27(78/82A) phosphorylation mutant, we further showed that phosphorylation of HSP27 at serine 78/82 residues was essential to TRAIL-triggered Src-Akt/ERK signaling transduction. Co-immunoprecipitation and confocal microscopy showed that HSP27 interacted with Src and scaffolding protein β-arrestin2 in response of TRAIL stimulation and suppression of HSP27 phosphorylation apparently disrupted the TRAIL-induced interaction of HSP27 and Src or interaction of HSP27 and β-arrestin2. We further demonstrated that β-arrestin2 mediated HSP27 action on TRAIL-induced Src activation, which was achieved by recruiting signaling complex of HSP27/β-arrestin2/Src in response to TRAIL. Taken together, our study revealed that HSP27 phosphorylation modulates TRAIL-triggered activation of Src-Akt/ERK pro-survival signaling via interacting with β-arrestin2 in HeLa cells.
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Shimei
authors.initials: S
authors.lastname: Qi
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Yinqiang
authors.initials: Y
authors.lastname: Xin
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Zhilin
authors.initials: Z
authors.lastname: Qi
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Yimiao
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Diao
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China. Electronic address: lanlei1978@gmail.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Lan
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, PR China. Electronic address: lanluo@nju.edu.cn.
authors.forename: Lan
authors.initials: L
authors.lastname: Luo
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, Jiangsu, PR China. Electronic address: yinzhimin@njnu.edu.cn.
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Yin
mesh_terms: D000840:Anisoles / Q000494:pharmacology; D017209:Apoptosis / Q000235:genetics*; D019390:Arrestins / Q000378:metabolism*; D045744:Cell Line, Tumor; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D055551:HSP27 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006360:Heat-Shock Proteins; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D007555:Isoxazoles / Q000494:pharmacology; D020935:MAP Kinase Signaling System; D018832:Molecular Chaperones; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*; D000071557:beta-Arrestins; D019061:src-Family Kinases / Q000378:metabolism; D000099190:MAP-Kinase-Activated Kinase 2
chemical_list: D000840:Anisoles; D019390:Arrestins; D048049:Extracellular Signal-Regulated MAP Kinases; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D007555:Isoxazoles; D018832:Molecular Chaperones; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D034741:RNA, Small Interfering; D053221:TNF-Related Apoptosis-Inducing Ligand; D000071557:beta-Arrestins; D019061:src-Family Kinases; D000099190:MAP-Kinase-Activated Kinase 2; C507623:5-(5-ethyl-2-hydroxy-4-methoxyphenyl)-4-(4-methoxyphenyl)isoxazole; C057725:HSPB1 protein, human; C505653:TNFSF10 protein, human
keywords: Akt; ERK; HSP27; Src; TRAIL; β-Arrestin