Evidence for a central role of protein kinase C in modulation of the hypoxic ventilatory response in the rat.

Abstract

Protein kinase C (PKC) has been implicated as a common mechanism in the transduction of various extracellular signals into the cell (29). PKC is ubiquitous in the central nervous system and is activated by Ca2+, phospholipids and diacylglycerol (DAG) or phorbol-esters to control many physiological processes (16). The PKC family consists of three major sub-groups of isoenzymes based on their molecular structure and co-factor requirements. One sub-group comprises the classical PKC α, β1, β2, and γ isoforms, all of which share a C2 region corresponding to the Ca2+binding site (23). In the other major subgroup containing the novel PKC δ, e, θ, η, and μ isoforms, the C2 region is absent, and activation may occur in the absence of Ca2+(14, 23, 33). Atypical isoforms such as PKC ξ, ι, and λ, also lack C2 as well as one of the repeated cysteine-rich zinc finger binding motifs within the Cl domain (24).