Premium
Calcium/calmodulin‐dependent protein kinase IIβ isoform is expressed in motor neurons during axon outgrowth and is part of slow axonal transport
Author(s) -
Lund Linda M.,
McQuarrie Irvine G.
Publication year - 2002
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.10162
Subject(s) - axon , calmodulin , gene isoform , biology , microbiology and biotechnology , sciatic nerve , protein kinase a , axoplasmic transport , calcium binding protein , cytoskeleton , calcium , neuroscience , kinase , chemistry , biochemistry , anatomy , cell , enzyme , gene , organic chemistry
Previously, we identified calcium/calmodulin‐dependent protein kinase IIβ (CaMKIIβ) mRNA in spinal motor neurons with 372 bp inserted in what corresponds to the “association” domain of the protein. This was interesting because known additions and deletions to CaMKIIβ mRNA are usually less than 100 bp in size and found in the “variable” region. Changes in the association domain of CaMKIIβ could influence substrate specificity, activity or intracellular targeting. We show that three variations of this insert are found in CNS neurons or sciatic motor neurons of Sprague–Dawley rats. We used PCR and nucleic acid sequencing to identify inserts of 114, 243, or 372 bases. We also show that addition of the 372 bases is associated with outgrowth of the axon (the standard CaMKIIβ downregulates when axon outgrowth occurs). Radiolabeling, immunoblots, and 2D PAGE identified this larger CaMKIIβ as part of the group of soluble proteins moving at the slowest rate of axonal transport (SCa) in sciatic motor neurons (∼1 mm/day). This group is composed mainly of structural proteins (e.g., tubulin) used to assemble the cytoskeleton of regrowing axons. Published 2002 Wiley‐Liss, Inc.