The specific activation of TRPC4 by Gi protein subtype.
The classical type of transient receptor potential channel (TRPC) is a molecular candidate for Ca(2+)-permeable cation channels in mammalian cells. Especially, TRPC4 has the similar properties to Ca(2+)-permeable nonselective cation channels (NSCCs) activated by muscarinic stimulation in visceral smooth muscles. In visceral smooth muscles, NSCCs activated by muscarinic stimulation were blocked by anti-Galphai/o antibodies. However, there is still no report which Galpha proteins are involved in the activation process of TRPC4. Among Galpha proteins, only Galphai protein can activate TRPC4 channel. The activation effect of Galphai was specific for TRPC4 because Galphai has no activation effect on TRPC5, TRPC6 and TRPV6. Coexpression with muscarinic receptor M2 induced TRPC4 current activation by muscarinic stimulation with carbachol, which was inhibited by pertussis toxin. These results suggest that Galphai is involved specifically in the activation of TRPC4.
Department of Physiology, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, Republic of Korea.
Jae-Pyo
JP
Jeon
Department of Physiology, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, Republic of Korea.
Kyu Pil
KP
Lee
Department of Physiology, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, Republic of Korea.
Eun Jung
EJ
Park
Department of Physiology, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, Republic of Korea.
Tae Sik
TS
Sung
Department of Physiology, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, Republic of Korea.
Byung Joo
BJ
Kim
Department of Physiology, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, Republic of Korea.
Ju-Hong
JH
Jeon
Department of Physiology, Seoul National University College of Medicine, 28 Yongon-Dong, Chongno-Gu, Seoul 110-799, Republic of Korea. Electronic address: insuk@plaza.snu.ac.kr.
Insuk
I
So
D000818:Animals; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D051960:GTP-Binding Protein alpha Subunit, Gi2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D051379:Mice; D043585:Receptor, Muscarinic M2 / Q000235:genetics; D050052:TRPC Cation Channels / Q000819:agonists* / Q000378:metabolism; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism
D015220:Calcium Channels; D043585:Receptor, Muscarinic M2; D050052:TRPC Cation Channels; C489571:TRPC4 ion channel; D050916:TRPV Cation Channels; C422827:TRPV6 protein, human; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D051960:GTP-Binding Protein alpha Subunit, Gi2