Mechanism of Assembly of G Protein βγ Subunits by Protein Kinase CK2-phosphorylated Phosducin-like Protein and the Cytosolic Chaperonin Complex

Abstract

Phosducin-like protein (PhLP) is a widely expressed binding partner of the G protein βγ subunit complex (Gβγ) that has been recently shown to catalyze the formation of the Gβγ dimer from its nascent polypeptides. Phosphorylation of PhLP at one or more of three consecutive serines (Ser-18, Ser-19, and Ser-20) is necessary for Gβγ dimer formation and is believed to be mediated by the protein kinase CK2. Moreover, several lines of evidence suggest that the cytosolic chaperonin complex (CCT) may work in concert with PhLP in the Gβγ-assembly process. The results reported here delineate a mechanism for Gβγ assembly in which a stable ternary complex is formed between PhLP, the nascent Gβ subunit, and CCT that does not include Gγ. PhLP phosphorylation permits the release of a PhLP·Gβ intermediate from CCT, allowing Gγ to associate with Gβ in this intermediate complex. Subsequent interaction of Gβγ with membranes releases PhLP for another round of assembly. Phosducin-like protein (PhLP) is a widely expressed binding partner of the G protein βγ subunit complex (Gβγ) that has been recently shown to catalyze the formation of the Gβγ dimer from its nascent polypeptides. Phosphorylation of PhLP at one or more of three consecutive serines (Ser-18, Ser-19, and Ser-20) is necessary for Gβγ dimer formation and is believed to be mediated by the protein kinase CK2. Moreover, several lines of evidence suggest that the cytosolic chaperonin complex (CCT) may work in concert with PhLP in the Gβγ-assembly process. The results reported here delineate a mechanism for Gβγ assembly in which a stable ternary complex is formed between PhLP, the nascent Gβ subunit, and CCT that does not include Gγ. PhLP phosphorylation permits the release of a PhLP·Gβ intermediate from CCT, allowing Gγ to associate with Gβ in this intermediate complex. Subsequent interaction of Gβγ with membranes releases PhLP for another round of assembly. Eukaryotic cells employ heterotrimeric G proteins to transduce a wide variety of hormonal, neuronal, and sensory signals that control numerous physiological processes. As a result, malfunctions in G protein pathways contribute to many diseases (1Rockman H.A. Koch W.J. Lefkowitz R.J. Nature. 2002; 415: 206-212Crossref PubMed Scopus (770) Google Scholar, 2Simonds W.F. J. Invest. Med. 2003; 51: 194-214Crossref PubMed Google Scholar, 3Gainetdinov R.R. Premont R.T. Bohn L.M. Lefkowitz R.J. Caron M.G. Annu. Rev. Neurosci. 2004; 27: 107-144Crossref PubMed Scopus (661) Google Scholar), and therapeutic agents targeting G protein-coupled receptors represent the single largest class of current pharmaceuticals (4Schoneberg T. Schulz A. Biebermann H. Hermsdorf T. Rompler H. Sangkuhl K. Pharmacol. Ther. 2004; 104: 173-206Crossref PubMed Scopus (242) Google Scholar). There are three fundamental steps in the propagation of a G protein-mediated signal. First, a ligand binds a receptor, resulting in a change in the packing of the seven transmembrane α-helices found in all G protein-coupled receptors. Second, the activated receptor catalyzes exchange of GDP for GTP on the α subunit of a heterotrimeric G protein (Gα) 2The abbreviations used are: Gα, α subunit of a heterotrimeric G protein; G, heterotrimeric GTP-binding protein; Pdc, phosducin; PhLP, phosducin-like protein; CCT, cytosolic chaperonin containing tailless complex polypeptide 1; CK2, protein kinase CK2; LC/MS/MS, liquid chromatography coupled with electrospray tandem mass spectrometry; CID, collision-induced dissociation; CHO, Chinese hamster ovary cell; HEK-293 cells, human embryonic kidney 293 cells; HA, hemagglutinin; Tricine, N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine.2The abbreviations used are: Gα, α subunit of a heterotrimeric G protein; G, heterotrimeric GTP-binding protein; Pdc, phosducin; PhLP, phosducin-like protein; CCT, cytosolic chaperonin containing tailless complex polypeptide 1; CK2, protein kinase CK2; LC/MS/MS, liquid chromatography coupled with electrospray tandem mass spectrometry; CID, collision-induced dissociation; CHO, Chinese hamster ovary cell; HEK-293 cells, human embryonic kidney 293 cells; HA, hemagglutinin; Tricine, N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine. on the intracellular surface of the receptor. GTP binding causes Gα to dissociate from the G protein βγ subunit complex (Gβγ). Third, the Gα·GTP and Gβγ complexes control the activity of effector enzymes and ion channels that regulate the intracellular concentration of second messengers (cyclic nucleotides, inositol phosphates, and Ca2+) and the plasma membrane electrical potential (mainly via K+ channels). Changes in these properties in turn orchestrate the cellular response to the stimulus (5Cabrera-Vera T.M. Vanhauwe J. Thomas T.O. Medkova M. Preininger A. Mazzoni M.R. Hamm H.E. Endocr. Rev. 2003; 24: 765-781Crossref PubMed Scopus (506) Google Scholar). Phosducin-like protein (PhLP) is a member of the phosducin gene family (6Flanary P.L. DiBello P.R. Estrada P. Dohlman H.G. J. Biol. Chem. 2000; 275: 18462-18469Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar, 7Blaauw M. Knol J.C. Kortholt A. Roelofs J. Ruchira Postma M. Visser A.J. Van Haastert P.J. EMBO J. 2003; 22: 5047-5057Crossref PubMed Scopus (44) Google Scholar, 8Miles M.F. Barhite S. Elliott M. Proc. Natl. Acad. Sci. S. A. PubMed Scopus Google that is believed to in G protein by of its to the Gβγ dimer with S. Proc. Natl. Acad. Sci. S. A. PubMed Scopus Google Scholar, M.F. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, Hamm H.E. J. Biol. Chem. 2000; 275: Full Text Full Text PDF PubMed Scopus Google Scholar). in and shown that PhLP binding to Gβγ its to with Gα or S. Proc. Natl. Acad. Sci. S. A. PubMed Scopus Google Scholar, M.F. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, M. S. 2000; PubMed Scopus Google Scholar, J. Biol. Chem. 2002; Full Text Full Text PDF PubMed Scopus Google Scholar, J. T. J. Biol. Chem. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar). these that the physiological of PhLP to G protein by the results of several this of the gene in the S. P. Proc. Natl. Acad. Sci. S. A. 2000; PubMed Scopus Google and in the M. Knol J.C. Kortholt A. Roelofs J. Ruchira Postma M. Visser A.J. Van Haastert P.J. EMBO J. 2003; 22: 5047-5057Crossref PubMed Scopus (44) Google the the of the Gβ Moreover, PhLP G protein in M. Knol J.C. Kortholt A. Roelofs J. Ruchira Postma M. Visser A.J. Van Haastert P.J. EMBO J. 2003; 22: 5047-5057Crossref PubMed Scopus (44) Google Scholar). another the of in in which PhLP in the by J. M. A. A. P. 2002; PubMed Scopus Google Scholar). of these are the of be by the Gβγ of PhLP has from the that PhLP with the cytosolic chaperonin containing complex polypeptide that the of and proteins Proc. Natl. Acad. Sci. S. A. 2002; PubMed Scopus Google Scholar). PhLP shown to with CCT a and not a the of the complex J. S. T. P.J. Proc. Natl. Acad. Sci. S. A. 2004; PubMed Scopus Google that PhLP binds CCT at the of the CCT the in a to a CCT that binds nascent polypeptide and to CCT for J. J. P. EMBO J. 2002; PubMed Scopus Google Scholar). these with the that Gβ A. A. A. P. K. K. S. J. M. J. M. K. H. H. A. J. J. T. M.F. M. M. Nature. 2002; 415: PubMed Scopus Google and proteins with seven to Gβ J. P. K. 2002; PubMed Scopus Google Scholar, K. S. EMBO J. 2003; 22: PubMed Scopus Google Scholar, A. A. A. 2003; Full Text Full Text PDF PubMed Scopus Google with CCT that PhLP a in the of that PhLP does for assembly of the Gβγ that the physiological of PhLP is not to G protein by Gβγ to G protein by Gβγ dimer formation T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). the of CCT in this T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar, J. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus (48) Google Scholar). Phosphorylation of PhLP by protein kinase in PhLP of phosphorylation a of three consecutive serines the J. T. J. Biol. Chem. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar). Phosphorylation of serines for Gβγ for these with PhLP to catalyze Gβγ dimer formation T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). The mechanism by which phosphorylation at these Gβγ dimer formation is not the of phosphorylation on PhLP The results of these evidence for a mechanism of Gβγ assembly that the formation of a ternary complex between PhLP, the nascent Gβ and PhLP phosphorylation is for the release of PhLP·Gβ from the CCT complex and the of Gγ with Gβ to the Gβγ and cells in with and with The cells to not used of human PhLP, PhLP and with and in the T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). of human PhLP at and in the by a and the T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). The the K. J. 2004; Google Scholar). The of all by The and in the from the and and phosphorylation of human PhLP in the in cells and chromatography Hamm H.E. J. Biol. Chem. 2000; 275: Full Text Full Text PDF PubMed Scopus Google Scholar). The proteins and by and in at and membranes Hamm H.E. J. Biol. Chem. 2000; 275: Full Text Full Text PDF PubMed Scopus Google Scholar). protein and the to be by Phosphorylation of PhLP by in and for at The phosphorylation by of PhLP to binding of or PhLP and its phosphorylation to CCT by PhLP to in containing and in a of to for at which the PhLP by for at with of by the of of a of and another at with The with the and proteins with of of on a and with a of J. S. T. P.J. Proc. Natl. Acad. Sci. S. A. 2004; PubMed Scopus Google by a of a with the and with a The of PhLP of to binding of and to membranes containing or PhLP Hamm H.E. J. Biol. Chem. 2000; 275: Full Text Full Text PDF PubMed Scopus Google Scholar). of PhLP and K. J. 2004; Google Scholar). in the from a chromatography that to the of from PhLP by collision-induced in a mass or ion cells in that the The cells with of or one of the phosphorylation to the The cells in of T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar), and the from the with of and of Proc. Natl. Acad. Sci. S. A. 2002; PubMed Scopus Google Scholar, T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). The in of and of on The with a of the and Gβγ cells in that be the with of of the and all the of by the cells and in of The complexes from of the with of Proc. Natl. Acad. Sci. S. A. 2002; PubMed Scopus Google Scholar, T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). The complexes in of and on for or on for Gβ the with a of a J. J.C. 2004; PubMed Scopus Google Scholar). the membranes for in in by for in a of in the and in a of The and T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). used to the of release of nascent Gβ from of HEK-293 cells with of or a the for the and the cells in of The and of to one and of to the The and of the proteins with CCT T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). The from the its The of in the CCT by that in the to the of the to expressed a of the to the of Gβ from The to a the to the the the by the of Gβ to CCT binding HEK-293 cells in and with of Pdc, or PhLP in and the with of of PhLP and of in cells and with of the on and for or the and a of the control phosphorylation is for the release of Gβ from CCT and interaction with Gγ. the of PhLP phosphorylation and Gγ on Gβ binding to CCT by HEK-293 cells with and the PhLP with to and for is in the represent the of the Gβ to the from three the of PhLP phosphorylation on the of Gβ release from CCT a HEK-293 cells with and the PhLP The in the with to or by and a The Gβ and of nascent in the CCT the nascent Gβ in the Gβ and a of the at the represent a of the from to a for are shown the the of Gγ on release of nascent from CCT in in HEK-293 cells in to and the of Gγ to CCT by HEK-293 cells with or PhLP with to and for is The in the CCT the from the binding HEK-293 cells in and with of PhLP in in of and with of and of protein with the binding PhLP, HEK-293 cells in and with of in from and with of and of Phosphorylation of PhLP on CCT and Gβγ to the of phosphorylation on PhLP the of phosphorylation on the binding of PhLP to its binding Gβγ and CCT, in human PhLP by CK2, resulting in a in the of the PhLP protein in The PhLP that phosphorylation the The of phosphorylation on CCT binding by the of PhLP to CCT from J. S. T. P.J. Proc. Natl. Acad. Sci. S. A. 2004; PubMed Scopus Google Scholar). PhLP CCT with a by the that of PhLP to of CCT from the these phosphorylation the of CCT by phosphorylation on the of PhLP to or to of with and that phosphorylation not change the binding of PhLP to of the Phosphorylation of phosphorylation that be for the in PhLP binding to CCT phosphorylation by mass PhLP by in and with and the resulting by electrospray tandem mass the collision-induced of a ion with of to the mass of a containing the of PhLP one for the and to the of the the ion to the of a and the formation of a at one of the serines in this that or in the The and all to the mass of that and not the on is a for phosphorylation with at the and J. 2003; PubMed Scopus Google Scholar). with to a and by of PhLP one and The for the and of which to the of the The with the The the of the not the serines of this serines and all be potential phosphorylation the and are and phosphorylation of a for phosphorylation of in a phosphorylation of a of the the mass suggest potential phosphorylation on Ser-19, and of Phosphorylation to the which of these is for the in PhLP binding to CCT, of the serines with in The resulting PhLP and binding to CCT in of one the in the in of this in in the binding from to of all three serines this phosphorylation a in the to that phosphorylation the for of the in PhLP binding to CCT to the and of a in binding with the of or with all three of the Ser-19, and to the in results that of the serines by mass contribute to the in PhLP binding to CCT and that phosphorylation are in this that all the phosphorylation in the mass is to that the to not change the binding of PhLP to CCT that the not the of the PhLP the interaction the of the in binding with the be to of the to be by CK2. of Phosphorylation in the phosphorylation of PhLP in in the in phosphorylation to PhLP phosphorylation in this PhLP to with a and the PhLP and with to the to the from the of a that be by in PhLP be to in in of that PhLP PhLP of the with PhLP that all of the PhLP in the cells The PhLP a with the PhLP and a with The of the of the to with the the The PhLP and a of the and The of in the that phosphorylation of or may be be results that is in cells and that phosphorylation the with and to The a single with PhLP that the The and a with to The the and phosphorylation at and that is for the The suggest that phosphorylation may be in the of or at or the of the a single with the PhLP, that the in is not a of or from at one phosphorylation in the Ser-19, and The of PhLP at and all The causes in the of the PhLP to the PhLP, the not the that of serines The in which all has the the and that is in cells, at in the of phosphorylation at serines and that phosphorylation causes a in PhLP The of change in with of not a to be the phosphorylation of this in phosphorylation at not or not change the of PhLP in of with in phosphorylation of the PhLP with PhLP, and the the The in of the PhLP between the in phosphorylation and that found in cells that is for PhLP phosphorylation in in with that the kinase J. T. J. Biol. Chem. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar). in the of the all the PhLP not that the in not by the these a for phosphorylation the serines and in of Phosphorylation on Gβγ and has recently been reported that of all three in the the of PhLP to the cellular of Gβγ T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar, J. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus (48) Google Scholar). this the phosphorylation of PhLP with and in HEK-293 cells, and the on Gβγ by the from and for and of the single phosphorylation not change Gβγ with of the or the and of the or the Gβ by and Gγ by with the Gβ and Gγ by and and of and in Gβγ that phosphorylation of at one the is for PhLP to in the of with phosphorylation the to this process. that phosphorylation of and in Gβγ Moreover, the in Gβγ by several of the PhLP to with the that these the of PhLP to Gβγ and are of The for Gβγ in the of PhLP is that PhLP the of Gβγ dimer assembly T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). which phosphorylation are for Gβγ the of the PhLP phosphorylation to catalyze Gβγ dimer assembly of the and of the in to in Gβγ dimer formation with PhLP The the by assembly of with for PhLP, the the with a of The and intermediate of and the PhLP in Gβγ assembly with a of Gβγ assembly results are to the Gβγ is one in the between the Gβγ and the Gβγ assembly Gβγ by the the of Gβγ assembly by be by the which Gβγ that the in the of Gβγ assembly is to the Gβγ in the to found in the of PhLP, the in assembly with the Ser-19, and is the Gβγ assembly and that phosphorylation in the are for PhLP to be in Gβγ assembly. Phosphorylation at one of the three results in with phosphorylation the The results that phosphorylation of or has on Gβγ assembly. Gβ CCT in a with between the in binding of PhLP to CCT phosphorylation of serines and the of phosphorylation of serines for activity in Gβγ assembly that the of PhLP phosphorylation on assembly may a for CCT in Gβγ assembly has not been T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). CCT does in the assembly with or interaction between Gβ and CCT has been in protein interaction interaction has been reported in the binding of Gβ and Gγ to CCT by of Gβ or Gγ in HEK-293 Gβ with CCT to a PhLP, Pdc, which does not CCT, not found in the CCT Gβ to be with CCT Gγ not with CCT the interaction with of the of Gβ with CCT with the results of the The in which PhLP binds CCT at the of the the J. S. T. P.J. Proc. Natl. Acad. Sci. S. A. 2004; PubMed Scopus Google that PhLP, and CCT a ternary complex in the of Gβγ a ternary complex does PhLP be to the binding of Gβ to CCT and this the of PhLP or Gβ on the binding of the to CCT As Gβ the binding of PhLP to CCT PhLP a in Gβ binding to CCT is that this in Gβ binding to CCT be by Gβγ assembly and release of the Gβγ dimer from this the of PhLP that not Gβγ assembly on Gβ binding to CCT PhLP and the a in which been T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). of these CCT, Gβγ assembly in a T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). of of these Gβ binding to CCT that in the of PhLP a ternary complex with Gβ and CCT that in the assembly process. is to that the binds Gβγ T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar), is to the complex between Gβ and that PhLP may more with CCT with PhLP Phosphorylation for the of Gβ from CCT and with the between the of the ternary complex by PhLP phosphorylation and the for PhLP phosphorylation in Gβγ the of Gγ on ternary complex formation with several PhLP Gβ in HEK-293 cells with Gγ and PhLP and the of Gβ with CCT of Gγ a in Gβ binding to CCT that by the of Gβ binding to CCT by of PhLP and to of Gγ. of PhLP Gβ binding to CCT and Gγ of on binding with the of PhLP and on Gβ binding to CCT in the of Gγ to on Gβγ assembly. PhLP Gβγ assembly T. Hamm H.E. EMBO J. 24: PubMed Scopus Google and of Gβ from CCT, PhLP the of Gβγ assembly by T. Hamm H.E. EMBO J. 24: PubMed Scopus Google and of Gβ from CCT by the Gβγ to the Gβγ PhLP in these that PhLP phosphorylation to Gβγ assembly by the of Gγ to release Gβ from the ternary complex. There are by which PhLP contribute to release of Gβ from a change in the ternary complex PhLP First, PhLP phosphorylation a that Gγ to Gβ in the ternary complex and the Gβγ The Gβγ be from Second, phosphorylation a that releases PhLP·Gβ from CCT, the Gγ binding on Gβ for Gβγ to between these the of Gγ and PhLP on the of of Gβ from CCT this cells Gβ with PhLP, or PhLP with for to the nascent and with the the cells and CCT The proteins by and the of in the Gβ the of PhLP or Gγ the of nascent Gβ from CCT with a of PhLP the by to a of PhLP not the Gγ with the by to a of Gγ and PhLP the to the in the of Gγ PhLP with Gβ to in the of Gγ of PhLP, and PhLP on the are with on the binding of Gβ to CCT and that PhLP phosphorylation is for the release of Gβ from the ternary complex. are to between the potential the of of Gβ from CCT PhLP in the of Gγ is with the second mechanism in which a PhLP·Gβ complex be to Gγ binding to not be in the mechanism in which Gγ binding be for release of Gβ from the of in the Gβ of Gγ with PhLP be by the second mechanism not by the the the release of Gβ from CCT Gγ in the of PhLP is with the this be by the second mechanism the PhLP to release Gβ from CCT for with Gγ. this the be by the formation of the Gβγ dimer and its with Gα and membranes the of Gγ in the release of Gβ from CCT, the of Gγ with Gβ and PhLP in CCT complexes Gγ with the of Gβ and the PhLP the CCT complexes and the for not found in of the CCT the that Gβ and PhLP be found these that Gγ does not with CCT in of its complexes with Gβ and the in that PhLP phosphorylation results in the release of a PhLP·Gβ complex from CCT that associate with Gγ to the Gβγ is by the reported that PhLP a stable complex with Gβ that does not include Gγ T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar). for Gβγ shown that PhLP in the assembly of Gβγ by binding the Gβ subunit and allowing Gγ to associate with Gβ T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar, J. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus (48) Google Scholar). Phosphorylation of PhLP at serines by for Gβγ assembly to the by which phosphorylation of serines to assembly Moreover, CCT been in the assembly the results J. S. T. P.J. Proc. Natl. Acad. Sci. S. A. 2004; PubMed Scopus Google Scholar, T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar, J. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus (48) Google Scholar). The current evidence for a mechanism the of CCT and PhLP phosphorylation in Gβγ assembly There are steps in this the nascent Gβ polypeptide binds is a stable complex that releases Gβ in the of PhLP binds a ternary complex. PhLP is not the ternary complex in a stable that does not release and the Gβγ assembly is PhLP is the the ternary complex in a that releases the PhLP·Gβ PhLP·Gβ from The of the complex that binds Gβ on the Gγ A. Full Text Full Text PDF PubMed Scopus Google Scholar), that the Gγ binding on Gβ be in the PhLP·Gβ Gγ binds Gβ a complex. complex is stable with a binding Hamm H.E. J. Biol. Chem. 2000; 275: Full Text Full Text PDF PubMed Scopus Google Scholar). the Gα binding and the membrane surface of Gβγ with the PhLP binding Hamm H.E. J. Biol. Chem. 2000; 275: Full Text Full Text PDF PubMed Scopus Google in the of Gα and PhLP be to be from with Gα the membrane and is to the plasma membrane M. S. M. Biol. 2002; PubMed Scopus Google Scholar). PhLP is to catalyze another round of Gβγ assembly. the of the PhLP and PhLP ternary complexes that not release PhLP·Gβ for Gγ stable ternary complexes the PhLP from ternary complexes of PhLP·Gβ for Gγ of the of PhLP which that PhLP Gβ and Gγ with CCT J. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus (48) Google or that PhLP a PhLP·Gβ complex that not Gγ T. Hamm H.E. EMBO J. 24: PubMed Scopus Google Scholar), are in the is that phosphorylation of PhLP its binding to CCT in the of Gβ PhLP phosphorylation necessary for the release of PhLP·Gβ from CCT in the of Gβ The between these may from in the of the and the of the in these may be from the of the complex J. S. T. P.J. Proc. Natl. Acad. Sci. S. A. 2004; PubMed Scopus Google Scholar). this PhLP shown to in at the of the CCT the CCT J. S. T. P.J. Proc. Natl. Acad. Sci. S. A. 2004; PubMed Scopus Google Scholar). one the phosphorylation of PhLP in to the and and in the the phosphorylation in to the and The binding of all are by and J. Biol. 2002; PubMed Scopus Google with the and binding a of the binding surface The phosphorylation of PhLP is a that is The of this concentration of that with the of the of phosphorylation the that the PhLP phosphorylation in to the the binding of PhLP to the of is that with Gβ may the of PhLP to on the of the CCT the phosphorylation may be in to the and between the on the and binding and the PhLP phosphorylation the ternary complex and the release of the PhLP·Gβ complex. be to the of this of Phosphorylation of the of phosphorylation of PhLP in Gβγ dimer to be is the of this phosphorylation is a kinase with many protein J. 2003; PubMed Scopus Google Scholar). of which are and phosphorylation to be by and assembly of the and by the of binding J. 2003; PubMed Scopus Google Scholar). the of PhLP, phosphorylation the of its not and the used here is not from the current phosphorylation to or of PhLP with CCT PhLP in and in the J. T. J. Biol. Chem. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar). is that Gβγ assembly is a in in assembly is that phosphorylation of the mechanism of Gβγ assembly and its by phosphorylation suggest that PhLP and its with Gβ and CCT be by to control the of Gβγ and the of G protein the to the of G