; In most cases, it is not known which receptors activate which G proteins to modulate which effectors in vivo. Reconstitution approaches have begun to provide invaluable information on the potential of specific G protein alpha or beta-gamma subunits to interact with particular receptors or effectors in vitro. Nevertheless, it is clear that there is a far wider range of potential interactions that occur in reconstituted systems than actually do occur in native membrane or cellular systems. This is exemplified by the finding that beta-adrenergic receptor activates both Gs and Gi equally in a reconstituted system, whereas this receptor activates Gs exclusively in an intact cardiac cell system. From these and other studies, it has become increasingly clear that although a receptor can activate several types of G proteins in vitro, the signaling pathways that the receptor regulates in vivo is much more restricted. This suggests that homology among signaling components and/or the artificial assay systems that have been employed in vitro do not provide the conditions necessary to distinguish what may be subtle, but important, mechanistic differences among signaling components that operate in vivo. There is increasing evidence that these mechanistic differences reflect not only biochemical, but also spatial differences, among signaling components. Hence, ascribing functional roles for G protein alpha and beta-gamma subunits in vivo remains a critical and formidable task. The focus of this application is on the development and application of new approaches to allow the role of the specific beta-gamma dimer in a particular receptor-effector pathway to be determined in vivo. Multiple approaches, including reverse genetics, biochemical, and immunological strategies, will be taken. Validation of results with all of these approaches will provide strong support for the role of a specific beta-gamma dimer in a particular receptor signaling pathway.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM058191-02
Application #
6019499
Study Section
Pharmacology A Study Section (PHRA)
Project Start
1998-09-01
Project End
2000-06-30
Budget Start
1999-09-01
Budget End
2000-06-30
Support Year
2
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Pennsylvania State University
Department
Physiology
Type
Schools of Medicine
DUNS #
129348186
City
Hershey
State
PA
Country
United States
Zip Code
17033
Leung, Tinchung; Humbert, Jasper E; Stauffer, Anna M et al. (2008) The orphan G protein-coupled receptor 161 is required for left-right patterning. Dev Biol 323:31-40
Chen, Hui; Leung, Tinchung; Giger, Kathryn E et al. (2007) Expression of the G protein gammaT1 subunit during zebrafish development. Gene Expr Patterns 7:574-83
Leung, Tinchung; Chen, Hui; Stauffer, Anna M et al. (2006) Zebrafish G protein gamma2 is required for VEGF signaling during angiogenesis. Blood 108:160-6
Sudol, Marius; Recinos, Claudia C; Abraczinskas, Jennifer et al. (2005) WW or WoW: the WW domains in a union of bliss. IUBMB Life 57:773-8
Robishaw, Janet D; Berlot, Catherine H (2004) Translating G protein subunit diversity into functional specificity. Curr Opin Cell Biol 16:206-9
Cheng, Keith C; Levenson, Robert; Robishaw, Janet D (2003) Functional genomic dissection of multimeric protein families in zebrafish. Dev Dyn 228:555-67
Robishaw, Janet D; Wang, Qin; Schwindinger, William F (2002) Ribozyme-mediated suppression of G protein gamma subunits. Methods Enzymol 344:435-51
Wang, Q; Jolly, J P; Surmeier, J D et al. (2001) Differential dependence of the D1 and D5 dopamine receptors on the G protein gamma 7 subunit for activation of adenylylcyclase. J Biol Chem 276:39386-93
Wang, Q; Mullah, B K; Robishaw, J D (1999) Ribozyme approach identifies a functional association between the G protein beta1gamma7 subunits in the beta-adrenergic receptor signaling pathway. J Biol Chem 274:17365-71