title: Abelson phosphorylation of CLASP2 modulates its association with microtubules and actin.
abstract: The Abelson (Abl) non-receptor tyrosine kinase regulates the cytoskeleton during multiple stages of neural development, from neurulation, to the articulation of axons and dendrites, to synapse formation and maintenance. We previously showed that Abl is genetically linked to the microtubule (MT) plus end tracking protein (+TIP) CLASP in Drosophila. Here we show in vertebrate cells that Abl binds to CLASP and phosphorylates it in response to serum or PDGF stimulation. In vitro, Abl phosphorylates CLASP with a Km of 1.89 µM, indicating that CLASP is a bona fide substrate. Abl-phosphorylated tyrosine residues that we detect in CLASP by mass spectrometry lie within previously mapped F-actin and MT plus end interaction domains. Using purified proteins, we find that Abl phosphorylation modulates direct binding between purified CLASP2 with both MTs and actin. Consistent with these observations, Abl-induced phosphorylation of CLASP2 modulates its localization as well as the distribution of F-actin structures in spinal cord growth cones. Our data suggest that the functional relationship between Abl and CLASP2 is conserved and provides a means to control the CLASP2 association with the cytoskeleton.
authors: Department of Cell Biology, Harvard Medical School, Boston, Massachusetts; Nikon Imaging Center, the University of Heidelberg, Bioquant, 69120, Heidelberg, Germany.
authors: Ulrike
authors: U
authors: Engel
authors: Yougen
authors: Y
authors: Zhan
authors: Jennifer B
authors: JB
authors: Long
authors: Scott N
authors: SN
authors: Boyle
authors: Bryan A
authors: BA
authors: Ballif
authors: Karel
authors: K
authors: Dorey
authors: Steven P
authors: SP
authors: Gygi
authors: Anthony J
authors: AJ
authors: Koleske
authors: David
authors: D
authors: Vanvactor
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002448:Cell Adhesion / Q000187:drug effects; D002522:Chlorocebus aethiops; D020439:Growth Cones / Q000187:drug effects / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000378:metabolism*; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism*; D008969:Molecular Sequence Data; D010766:Phosphorylation / Q000187:drug effects; D019000:Phosphotyrosine / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D016315:Proto-Oncogene Proteins c-abl / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D013379:Substrate Specificity / Q000187:drug effects; D014981:Xenopus
chemical_list: D000199:Actins; C506523:CLASP2 protein, mouse; D008869:Microtubule-Associated Proteins; D010982:Platelet-Derived Growth Factor; D019000:Phosphotyrosine; D016315:Proto-Oncogene Proteins c-abl
keywords: Abelson kinase; Abl; CLASP; microtubule; tyrosine phosphorylation