title: Molecular mechanism of ERK dephosphorylation by striatal-enriched protein tyrosine phosphatase.
abstract: Striatal-enriched tyrosine phosphatase (STEP) is an important regulator of neuronal synaptic plasticity, and its abnormal level or activity contributes to cognitive disorders. One crucial downstream effector and direct substrate of STEP is extracellular signal-regulated protein kinase (ERK), which has important functions in spine stabilisation and action potential transmission. The inhibition of STEP activity toward phospho-ERK has the potential to treat neuronal diseases, but the detailed mechanism underlying the dephosphorylation of phospho-ERK by STEP is not known. Therefore, we examined STEP activity toward para-nitrophenyl phosphate, phospho-tyrosine-containing peptides, and the full-length phospho-ERK protein using STEP mutants with different structural features. STEP was found to be a highly efficient ERK tyrosine phosphatase that required both its N-terminal regulatory region and key residues in its active site. Specifically, both kinase interaction motif (KIM) and kinase-specific sequence of STEP were required for ERK interaction. In addition to the N-terminal kinase-specific sequence region, S245, hydrophobic residues L249/L251, and basic residues R242/R243 located in the KIM region were important in controlling STEP activity toward phospho-ERK. Further kinetic experiments revealed subtle structural differences between STEP and HePTP that affected the interactions of their KIMs with ERK. Moreover, STEP recognised specific positions of a phospho-ERK peptide sequence through its active site, and the contact of STEP F311 with phospho-ERK V205 and T207 were crucial interactions. Taken together, our results not only provide the information for interactions between ERK and STEP, but will also help in the development of specific strategies to target STEP-ERK recognition, which could serve as a potential therapy for neurological disorders. Regulation of phospho-ERK by STEP underlies important neuronal activities. A detailed enzymologic characterisation and cellular studies of STEP revealed that specific residues in KIM and active site mediated ERK recognition. Structural differences between the KIM-ERK interfaces and the active site among different ERK phosphatases could be targeted to develop specific STEP inhibitor, which has therapeutic potential for neurological disorders. PKA, protein kinase A & NGF, nerve growth factor.
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Li
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Provincial Hospital affiliated to Shandong University, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Di-Dong
authors.initials: DD
authors.lastname: Xie
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.|Weifang Medical University,Weifang, Shandong, 261042, China.
authors.forename: Jun-Hong
authors.initials: JH
authors.lastname: Dong
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Department of Physiology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Qilu Hospital, Shandong University, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Kang-Shuai
authors.initials: KS
authors.lastname: Li
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Department of Physiology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Su
authors.affiliation: School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China.
authors.forename: Lai-Zhong
authors.initials: LZ
authors.lastname: Chen
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Qilu Hospital, Shandong University, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Yun-Fei
authors.initials: YF
authors.lastname: Xu
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Department of Physiology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Wang
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Weihai campus, Shandong University, Weihai, Shandong, 264209, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Gong
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Guo-Ying
authors.initials: GY
authors.lastname: Cui
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Department of Physiology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Yu
authors.affiliation: Department of Physiology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Physiology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yao
authors.affiliation: Provincial Hospital affiliated to Shandong University, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Xin
authors.affiliation: School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong, 250012, China.
authors.forename: Min-Yong
authors.initials: MY
authors.lastname: Li
authors.affiliation: Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Kun-Hong
authors.initials: KH
authors.lastname: Xiao
authors.affiliation: Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China, 518055.
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: An
authors.affiliation: Vascular Biology Center, Department of Cellular Biology and Anatomy, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Huo
authors.affiliation: Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.|Shandong University, School of Life Sciences, Jinan, Shandong, 250021, China.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Xu
authors.affiliation: Key Laboratory Experimental Teratology of the Ministry of Education and Department of Biochemistry and Molecular Biology, Shandong University, School of Medicine, Jinan, Shandong, 250012, China.|Provincial Hospital affiliated to Shandong University, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Jin-Peng
authors.initials: JP
authors.lastname: Sun
authors.affiliation: Provincial Hospital affiliated to Shandong University, Jinan, Shandong, 250012, China.|Shandong Provincial School Key laboratory for Protein Science of Chronic Degenerative Diseases, Jinan, Shandong, 250012, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Pang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020134:Catalytic Domain; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D016716:PC12 Cells; D010766:Phosphorylation; D054558:Protein Tyrosine Phosphatases, Non-Receptor / Q000235:genetics / Q000378:metabolism*; D051381:Rats
chemical_list: D019950:Mitogen-Activated Protein Kinase 1; D054558:Protein Tyrosine Phosphatases, Non-Receptor; C489931:Ptpn5 protein, rat
keywords: ERK; neurological disorders; phosphatase; phosphorylation; striatal enriched tyrosine phosphatases; synaptic plasticity