Open Access Green möglich sobald Postprint bei der ZB eingereicht worden ist.
betaIV spectrin, a new spectrin localized at axon initial segments and nodes of ranvier in the central and peripheral nervous system.
J. Cell Biol. 151, 985-1002 (2000)
We report the identification of betaIV spectrin, a novel spectrin isolated as an interactor of the receptor tyrosine phosphatase-like protein ICA512. The betaIV spectrin gene is located on human and mouse chromosomes 19q13.13 and 7b2, respectively. Alternative splicing of betaIV spectrin generates at least four distinct isoforms, numbered betaIVSigma1-betaIVSigma4 spectrin. The longest isoform (betaIVSigma1 spectrin) includes an actin-binding domain, followed by 17 spectrin repeats, a specific domain in which the amino acid sequence ERQES is repeated four times, several putative SH3-binding sites and a pleckstrin homology domain. betaIVSigma2 and betaIVSigma3 spectrin encompass the NH(2)- and COOH-terminal halves of betaIVSigma1 spectrin, respectively, while betaIVSigma4 spectrin lacks the ERQES and the pleckstrin homology domain. Northern blots revealed an abundant expression of betaIV spectrin transcripts in brain and pancreatic islets. By immunoblotting, betaIVSigma1 spectrin is recognized as a protein of 250 kD. Anti-betaIV spectrin antibodies also react with two additional isoforms of 160 and 140 kD. These isoforms differ from betaIVSigma1 spectrin in terms of their distribution on subcellular fractionation, detergent extractability, and phosphorylation. In islets, the immunoreactivity for betaIV spectrin is more prominent in alpha than in beta cells. In brain, betaIV spectrin is enriched in myelinated neurons, where it colocalizes with ankyrin(G) 480/270-kD at axon initial segments and nodes of Ranvier. Likewise, betaIV spectrin is concentrated at the nodes of Ranvier in the rat sciatic nerve. In the rat hippocampus, betaIVSigma1 spectrin is detectable from embryonic day 19, concomitantly with the appearance of immunoreactivity at the initial segments. Thus, we suggest that betaIVSigma1 spectrin interacts with ankyrin(G) 480/270-kD and participates in the clustering of voltage-gated Na(+) channels and cell-adhesion molecules at initial segments and nodes of Ranvier.
Impact Factor
Scopus SNIP
Altmetric
0.000
0.000
Anmerkungen
Besondere Publikation
Auf Hompepage verbergern
Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Sprache
englisch
Veröffentlichungsjahr
2000
HGF-Berichtsjahr
0
ISSN (print) / ISBN
0021-9525
e-ISSN
1540-8140
Zeitschrift
Journal of Cell Biology, The
Quellenangaben
Band: 151,
Heft: 5,
Seiten: 985-1002
Verlag
Rockefeller University Press
Begutachtungsstatus
Peer reviewed
Institut(e)
Institute of Pancreatic Islet Research (IPI)
POF Topic(s)
90000 - German Center for Diabetes Research
Forschungsfeld(er)
Helmholtz Diabetes Center
PSP-Element(e)
G-502600-001
PubMed ID
11086001
Erfassungsdatum
2000-12-31