title: Involvement of Src in the membrane skeletal complex, MPP6-4.1G, in Schmidt-Lanterman incisures of mouse myelinated nerve fibers in PNS.
abstract: Schmidt-Lanterman incisures (SLIs) are a specific feature of myelinated nerve fibers in the peripheral nervous system (PNS). In this study, we report localization of a signal transduction protein, Src, in the SLIs of mouse sciatic nerves, and its phosphorylation states in Y527 and Y418 (P527 and P418, respectively) under normal conditions or deletion of a membrane skeletal protein, 4.1G. In adult mouse sciatic nerves, Src was immunolocalized in SLIs as a cone-shape, as well as in paranodes and some areas of structures reminiscent of Cajal bands. By immunostaining in normal nerves, P527-Src was strongly detected in SLIs, whereas P418-Src was much weaker. Developmentally, P418-Src was detected in SLIs of early postnatal mouse sciatic nerves. The staining patterns for P527 and P418 in normal adult nerve fibers were opposite to those in primary culture Schwann cells and a Schwannoma cell line, RT4-D6P2T. In 4.1G-deficient nerve fibers, which had neither 4.1G nor the membrane protein palmitoylated 6 (MPP6) in SLIs, the P418-Src immunoreactivity in SLIs was clearly detected at a stronger level than that in the wild type. An immunoprecipitation study revealed Src interaction with MPP6. These findings indicate that the Src-MPP6-4.1G protein complex in SLIs has a role in signal transduction in the PNS.
authors.affiliation: Department of Occupational Therapy, School of Health Sciences, Shinshu University School of Medicine, Matsumoto City, Nagano, Japan. nobuot@shinshu-u.ac.jp
authors.forename: Nobuo
authors.initials: N
authors.lastname: Terada
authors.forename: Yurika
authors.initials: Y
authors.lastname: Saitoh
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Ohno
authors.forename: Masayuki
authors.initials: M
authors.lastname: Komada
authors.forename: Junji
authors.initials: J
authors.lastname: Yamauchi
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ohno
mesh_terms: D000818:Animals; D051528:Guanylate Kinases / Q000032:analysis / Q000378:metabolism*; D058635:Lipid-Linked Proteins / Q000032:analysis / Q000378:metabolism*; D008565:Membrane Proteins; D051379:Mice; D018345:Mice, Knockout; D008840:Microfilament Proteins / Q000032:analysis / Q000172:deficiency / Q000378:metabolism*; D009413:Nerve Fibers, Myelinated / Q000378:metabolism*; D017933:Peripheral Nervous System / Q000166:cytology*; D010766:Phosphorylation; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: C540651:Epb4.1l2 protein, mouse; D058635:Lipid-Linked Proteins; C569941:MPP6 protein, mouse; D008565:Membrane Proteins; D008840:Microfilament Proteins; D019061:src-Family Kinases; D051528:Guanylate Kinases