TY - JOUR
T1 - Gravin dynamics regulates the subcellular distribution of PKA
AU - Yan, Xiaohong
AU - Walkiewicz, Magdalena
AU - Carlson, Jennifer
AU - Leiphon, Laura
AU - Grove, Bryon
N1 - Funding Information:
This work was supported in part by seed funds from the University of North Dakota. Imaging studies were conducted in the UNDSMHS Basic Sciences Imaging Center which is supported in part by COBRE grant NIH P20RR017699-07. We thank Dr. Patrick Carr for reading the manuscript and providing valuable comments.
PY - 2009/4/15
Y1 - 2009/4/15
N2 - Gravin, a multivalent A-kinase anchoring protein (AKAP), localizes to the cell periphery in several cell types and is postulated to target PKA and other binding partners to the plasma membrane. An N-terminal myristoylation sequence and three regions rich in basic amino acids are proposed to mediate this localization. Reports indicating that phorbol ester affects the distribution of SSeCKS, the rat orthologue of gravin, further suggest that PKC may also regulate the subcellular distribution of gravin, which in turn may affect PKA distribution. In this study, quantitative confocal microscopy of cells expressing full-length and mutant gravin-EGFP constructs lacking the proposed targeting domains revealed that either the N-myristoylation site or the polybasic regions were sufficient to target gravin to the cell periphery. Moreover, phorbol ester treatment induced redistribution of gravin-EGFP from the cell periphery to a juxtanuclear vesicular compartment, but this required the presence of the N-myristoylation site. Confocal microscopy further revealed that not only did gravin-EGFP target a PKA RII-ECFP construct to the cell periphery, but PKC activation resulted in redistribution of the gravin and PKA constructs to the same subcellular site. It is postulated that this dynamic response by gravin to PKC activity may mediate PKC dependent control of PKA activity.
AB - Gravin, a multivalent A-kinase anchoring protein (AKAP), localizes to the cell periphery in several cell types and is postulated to target PKA and other binding partners to the plasma membrane. An N-terminal myristoylation sequence and three regions rich in basic amino acids are proposed to mediate this localization. Reports indicating that phorbol ester affects the distribution of SSeCKS, the rat orthologue of gravin, further suggest that PKC may also regulate the subcellular distribution of gravin, which in turn may affect PKA distribution. In this study, quantitative confocal microscopy of cells expressing full-length and mutant gravin-EGFP constructs lacking the proposed targeting domains revealed that either the N-myristoylation site or the polybasic regions were sufficient to target gravin to the cell periphery. Moreover, phorbol ester treatment induced redistribution of gravin-EGFP from the cell periphery to a juxtanuclear vesicular compartment, but this required the presence of the N-myristoylation site. Confocal microscopy further revealed that not only did gravin-EGFP target a PKA RII-ECFP construct to the cell periphery, but PKC activation resulted in redistribution of the gravin and PKA constructs to the same subcellular site. It is postulated that this dynamic response by gravin to PKC activity may mediate PKC dependent control of PKA activity.
KW - AKAP12
KW - Confocal microscopy
KW - Fluorescent proteins
KW - Gravin
KW - PKA
KW - PKC
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U2 - 10.1016/j.yexcr.2008.12.026
DO - 10.1016/j.yexcr.2008.12.026
M3 - Article
C2 - 19210988
AN - SCOPUS:63049128289
SN - 0014-4827
VL - 315
SP - 1247
EP - 1259
JO - Experimental Cell Research
JF - Experimental Cell Research
IS - 7
ER -