title: Coordinate expression of the alpha and beta subunits of heterotrimeric G proteins involves regulation of protein degradation in CHO cells.
abstract: Individual cell types express a characteristic balance between heterotrimeric G protein alpha and betagamma subunits, but little is known about the regulatory mechanism. We systemically examined the regulatory mechanism in CHO cells. We found that expression of Galphas, Galphai2, and Galphaq proteins increased in direct proportion to the increase of Gbeta1gamma2 overexpressed transiently. Expression of Gbeta protein also increased following overexpression of Galphas, Galphai2, and Galphaq. The Gbetagamma overexpression stimulated degradation of Gbeta in contrast to reduction of Galphas degradation. We conclude that coordinate expression of the G protein subunits involves regulation of protein degradation via proteasome in CHO cells.
authors.affiliation: Department of Biochemistry and Cancer Research Institute, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-799, South Korea.
authors.forename: Yun-Il
authors.initials: YI
authors.lastname: Lee
authors.forename: So-Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Chin-Ho
authors.initials: CH
authors.lastname: Cho
authors.forename: MiRan
authors.initials: M
authors.lastname: Seo
authors.forename: Du-Hyong
authors.initials: DH
authors.lastname: Cho
authors.forename: Sahng-June
authors.initials: SJ
authors.lastname: Kwak
authors.forename: Yong-Sung
authors.initials: YS
authors.lastname: Juhnn
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D044385:GTP-Binding Protein alpha Subunits / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D044387:GTP-Binding Protein beta Subunits / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D015151:Immunoblotting; D007976:Leupeptins / Q000494:pharmacology; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D044385:GTP-Binding Protein alpha Subunits; D044387:GTP-Binding Protein beta Subunits; D007976:Leupeptins; D011994:Recombinant Proteins; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde