To Explore The New Protein Factors Of G Protein Signal Transduction Pathways With Yeast Two And Three Hybrid System

Heterotrimeric G proteins play vital roles in cell signal transduction pathways for the soluble and cell-contact signals that regulate normal growth and differentiation. It consists of Gα.Gβ and Gγ subunits. Although there are many numbers of each subunit (20 α, 6β and 12γ ) are known, four main classes of G proteins can be distinguished: Gs ( activates adenylyl cyclase); Gi (inhibits adenylyl cyclase), Gq (activates phospholipase C) and G α 12/13 ( activates P115 Rho EGF to regulate Rho and stress fiber formation). Gα ,G β and G β γ dimmer independently behave as effectors in cell signal transduction. Nowadays, exploring the new effectors of G β γ dimmer and exploring the individual role of G β or G γ of G β γ dimmer subunits in cellular signal transduction is becoming hot research spots. G β 1 subunit can interact with its effectors such as adenylyl cyclase type 2 ( AC-ll) and the muscarinic atrial potassium channel (GIRKI) by its N-terminal 100-residue specificity . But there are still other new coming effectors to be discovered. At present, 12 isoforms of G γ subunits have been found. And the biological properties of the β γ complex containing γ 1 are noticeably different from those of β γ complexes containing others γ subunits. Some other researches shows that G γ subunit might affect the G β γ dimmer's selectivity.To explore the role of G β or G γ of G β γ dimmer subunits and to hunt for novel effectors of G β or G β γ dimmer, we choose G β 1 or G β 1 γ 2 subunits as bait protein factors, and applied yeast two- hybrid system or our own established yeast three hybrid system to screen human brain cDNA library. Furthermore, we testified the interaction between "bait protein factor"...