title: Differences in c-Jun N-terminal kinase recognition and phosphorylation of closely related stathmin-family members.
abstract: The stathmin (STMN) family of tubulin-binding phosphoproteins are critical regulators of interphase microtubule dynamics and organization in a broad range of cellular processes. c-Jun N-terminal kinase (JNK) signalling to STMN family proteins has been implicated specifically in neuronal maturation, degeneration and cell stress responses more broadly. Previously, we characterized mechanisms underlying JNK phosphorylation of STMN at proline-flanked serine residues (Ser25 and Ser38) that are conserved across STMN-like proteins. In this study, we demonstrated using in vitro kinase assays and alanine replacement of serine residues that JNK phosphorylated the STMN-like domain (SLD) of SCG10 on Ser73, consistent with our previous finding that STMN Ser38 was the primary JNK target site. In addition, we confirmed that a JNK binding motif ((41)KKKDLSL(47)) that facilitates JNK targeting of STMN is conserved in SCG10. In contrast, SCLIP was phosphorylated by JNK primarily on Ser60 which corresponds to Ser25 on STMN. Moreover, although the JNK-binding motif identified in STMN and SCG10 was not conserved in SCLIP, JNK phosphorylation of SCLIP was inhibited by a substrate competitive peptide (TI-JIP) highlighting kinase-substrate interaction as required for JNK targeting. Thus, STMN and SCG10 are similarly targeted by JNK but there are clear differences in JNK recognition and phosphorylation of the closely related family member, SCLIP.
authors.affiliation: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria, Australia.
authors.forename: Yan Y
authors.initials: YY
authors.lastname: Yip
authors.affiliation: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria, Australia.
authors.forename: Yvonne Y C
authors.initials: YY
authors.lastname: Yeap
authors.affiliation: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria, Australia.
authors.forename: Marie A
authors.initials: MA
authors.lastname: Bogoyevitch
authors.affiliation: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria, Australia. Electronic address: ngd@unimelb.edu.au.
authors.forename: Dominic C H
authors.initials: DC
authors.lastname: Ng
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D017124:Conserved Sequence; D006801:Humans; D020935:MAP Kinase Signaling System; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D048055:Mitogen-Activated Protein Kinase 8 / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000737:chemistry; D050777:Stathmin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D008565:Membrane Proteins; D011994:Recombinant Proteins; C493995:STMN1 protein, human; C063314:STMN2 protein, human; C112285:STMN3 protein, human; D050777:Stathmin; D012694:Serine; D048055:Mitogen-Activated Protein Kinase 8
keywords: Phosphorylation; SCG10; SCLIP; Stathmin; c-Jun N-terminal kinase