A 20-amino acid module of protein kinase C∈ involved in translocation and selective targeting at cell-cell contacts

Abstract

In the pituitary gland, activated protein kinase C (PKC) isoforms accumulate either selectively at the cell-cell contact (α and ∈) or at the entire plasma membrane (β1 and δ). The molecular mechanisms underlying these various subcellular locations are not known. Here, we demonstrate the existence within PKC∈ of a cell-cell contact targeting sequence (3CTS) that, upon stimulation, is capable of targeting PKCδ, chimerin-α1, and the PKC∈ C1 domain to the cell-cell contact. We show that this selective targeting of PKC∈ is lost upon overexpression of 3CTS fused to a (R-Ahx-R)4 (where Ahx is 6-aminohexanoic acid) vectorization peptide, reflecting a dominant-negative effect of the overexpressed 3CT..