Coordinated Movement of RACK1 with Activated βIIPKC

• Published in: The Journal of biological chemistry 1999-09, Vol.274 (38), p.27039-27046
• Main Authors: Ron, Dorit, Jiang, Zhan, Yao, Lina, Vagts, Alicia, Diamond, Ivan, Gordon, Adrienne
• Format: Article
• Language: English
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.274.38.27039

Protein kinase C (PKC) isozymes move upon activation from one intracellular site to another. PKC-binding proteins, such as receptors for activated C kinase (RACKs), play an important role in regulating the localization and diverse functions of PKC isozymes. RACK1, the receptor for activated βIIPKC, determines the localization and functional activity of βIIPKC. However, the mechanism by which RACK1 localizes activated βIIPKC is not known. Here, we provide evidence that the intracellular localization of RACK1 changes in response to PKC activation. In Chinese hamster ovary cells transfected with the dopamine D2L receptor and in NG108-15 cells, PKC activation by either phorbol ester or a dopamine D2 receptor agonist caused the movement of RACK1. Moreover, PKC activation resulted in the in situ association and movement of RACK1 and βIIPKC to the same intracellular sites. Time course studies indicate that PKC activation induces the association of the two proteins prior to their co-movement. We further show that association of RACK1 and βIIPKC is required for the movement of both proteins. Our results suggest that RACK1 is a PKC shuttling protein that moves βIIPKC from one intracellular site to another.