RDJ2 (DNAJA2) chaperones neural G protein signaling pathways.
A number of structurally divergent proteins with J domains, called J proteins, interact with and activate the ATPase of Hsp70s, thereby harnessing the ATPase activity for conformational work on target proteins. The precise role of most mammalian J proteins remains undefined. In this paper, we demonstrate that transient expression of the J protein, Rdj2, in HEK 293 cells increased cellular cyclic adenosine monophosphate (cAMP) levels in the presence of the beta-adrenergic agonist isoproterenol. In CNS-derived catecholaminergic neuronal cell line (CAD) neuroblastoma cells, expression of Rdj2 increased isoproterenol-stimulated phosphorylation of cAMP response element binding protein (CREB). Moreover, we have characterized the binding properties of Rdj2 and observed a direct interaction between Rdj2 and receptor-coupled trimeric GTP-binding proteins (G proteins). We further show that the composition of the Rdj2-chaperone complex and the cysteine string protein (CSPalpha)-chaperone complex, another J protein, is distinct. Our data demonstrate that Rdj2 modulates G protein signaling and further suggest that chaperoning G proteins is an emerging theme of the J protein network.
Rosales-Hernandez
Alma
A
Hotchkiss Brain Institute, Department of Physiology and Biophysics, University of Calgary, Calgary, AB, Canada T2N 4N1.
Beck
Katy E
KE
Zhao
Xiaoxi
X
Braun
Andrew P
AP
Braun
Janice E A
JE
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D004967:Estrogens / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism*; D050883:HSC70 Heat-Shock Proteins / Q000378:metabolism; D050957:HSP110 Heat-Shock Proteins / Q000378:metabolism; D050956:HSP40 Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D051379:Mice; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D009420:Nervous System / Q000187:drug effects / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects
D017362:Cyclic AMP Response Element-Binding Protein; D004967:Estrogens; D050883:HSC70 Heat-Shock Proteins; D050957:HSP110 Heat-Shock Proteins; D050956:HSP40 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D018832:Molecular Chaperones; D000242:Cyclic AMP; D019204:GTP-Binding Proteins