Calcium Calmodulin Dependent Kinase II in Cat Visual Cortex and Its Development

Abstract

A monoclonal antibody against the α-subunit of calcium/calmodulin-dependent protein kinase II (CAM-K II) was used to visualize the kinase in developing kitten visual cortex. CAM-K II was first expressed in neurons of the deep cortical layers (V and VI) at postnatal day 1–4 and appeared in the remaining cortical layers within the first 2 weeks. The level of immunoreactivity declined in cells of layer V and upper layer VI at about 30–40 days of age. By postnatal day 90, the most densely labelled neurons were concentrated in cortical layers II, III, lower layer IV and in layer VI. This laminar pattern remained constant into adulthood. EM studies showed that the kinase was found in both pre- and postsynaptic locations. About twice as many immunopositive neurons were found in cortical layers II-IV and VI in young adult cats when geniculate input was removed by an unilateral thalamic lesion performed early in life. These results indicate that expression of CAM-K II is developmentally regulated in visual cortical neurons; the alteration of immunoreactivity after early LGN lesions suggests that the level of the kinase (or its α-subunit) is also regulated by cortical input.

A comprehensive characterization of brain and retina synaptic vesicle proteome by quantitative mass spectrometry.

“…One of the well-known pathways is calmodulin-dependent phosphorylation cascade leading to phosphorylation of synapsin (Deremer et al, 1992a;Deremer et al, 1992b;Jia et al, 1992;Sihra et al, 1992). Synapsin contains a short Nterminal domain (20 residues, conserved for phosphorylation at seven sites by multiple protein kinases, a linker sequence and a large central C domain (300 residues) conserved in the synapsin family.…”