Calcium/calmodulin-dependent protein kinase II expression in motor neurons: Effect of axotomy

✍ Scribed by Lund, Linda M. ;McQuarrie, Irvine G.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 391 KB
• Volume: 33
• Category: Article
• ISSN: 0022-3034
• DOI: 10.1002/(sici)1097-4695(19971120)33:6<796::aid-neu7>3.0.co;2-4

✦ Synopsis

Although Ca 2/ /calmodulin-depen-mRNA increase. We were unable to find CaM kinase dent (CaM) protein kinase II isoforms are present in IIa immunoreactivity before or after axotomy in scithe nervous system in high amounts, many aspects of atic motor neuron cell bodies, suggesting that CaM in vivo expression, localization, and function remain kinase IIa is in the axons or dendrites, or otherwise unexplored. During development, CaM kinase IIa and unavailable to the antibody. Using rats with crush IIb are differentially expressed. Here, we examined lesions, we radiolabeled axonal proteins being synthe-CaM kinase II isoforms in Sprague-Dawley rat sciatic sized in the cell body and used two-dimensional polymotor neurons before and after axotomy. We cut the acrylamide gel electrophoresis with Western blots to L4-5 spinal nerves unilaterally and exposed the proxidentify CaM kinase IIa as a component of slow axoimal nerve stumps to a fluoroprobe, to retrogradely nal transport. This differential regulation and expreslabel the neurons of origin. Anti-CaM kinase IIb antision of kinase isoforms suggests separate and unique body showed immunoreactivity in motor neurons, intracellular roles. Because we find CaM kinase IIb which decreased to low levels by 4 days after axotomy. down-regulates during axonal regrowth, its role in We found a similar response by in situ hybridization these neurons may be related to synaptic transmission. with riboprobes. The decrease in expression of mRNA CaM kinase IIa appears to support axonal regrowth. and protein was confined to fluorescent motor neu-