Coordinate expression of the alpha and beta subunits of heterotrimeric G proteins involves regulation of protein degradation in CHO cells.
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.
Lee
Yun-Il
YI
Department of Biochemistry and Cancer Research Institute, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-799, South Korea.
Kim
So-Young
SY
Cho
Chin-Ho
CH
Seo
MiRan
M
Cho
Du-Hyong
DH
Kwak
Sahng-June
SJ
Juhnn
Yong-Sung
YS
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
D044385:GTP-Binding Protein alpha Subunits; D044387:GTP-Binding Protein beta Subunits; D007976:Leupeptins; D011994:Recombinant Proteins; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde