TY - JOUR
T1 - Involvement of rho p21 in the GTP-enhanced calcium ion sensitivity of smooth muscle contraction
AU - Hirata, K. I.
AU - Kikuchi, A.
AU - Sasaki, T.
AU - Kuroda, S.
AU - Kaibuchi, K.
AU - Matsuura, Y.
AU - Seki, H.
AU - Saida, K.
AU - Takai, Y.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1992
Y1 - 1992
N2 - In the rabbit mesenteric arterial smooth muscle skinned by saponin, Ca2+ induced contraction in a concentration-dependent manner. Guanosine 5'-(3-O- thio)triphosphate (GTPγS), a non-hydrolyzable GTP analogue, lowered the Ca2+ concentrations required for this contraction and increased the Ca2+ sensitivity of the skinned smooth muscle contraction. GTPγS alone did not induce the contraction in the absence of Ca2+. This GTPγS-enhanced Ca2+ sensitivity was completely abolished by an exoenzyme of Staphylococcus aureus, named EDIN, and an exoenzyme of Clostridium botulinum, named C3, both of which are known to ADP-ribosylate the rho p21 family that belongs to the ras p21-like small GTP-binding protein superfamily. The GTPγS-bound form of rhoA p21 overcame the inhibitory action of EDIN. smg p21B, another small GTP- binding protein, was inactive. EDIN ADP-ribosylated a protein, which was most likely to be rho p21, in the skinned smooth muscle. The GTPγS-bound form of rhoA p21, but not the GDP-bound form, substituted for GTPγS and enhanced the Ca2+ sensitivity of the skinned smooth muscle contraction. smg p21B was inactive. These results indicate that rhoA p21 is involved in the GTPγS- enhanced Ca2+ sensitivity of the smooth muscle contraction.
AB - In the rabbit mesenteric arterial smooth muscle skinned by saponin, Ca2+ induced contraction in a concentration-dependent manner. Guanosine 5'-(3-O- thio)triphosphate (GTPγS), a non-hydrolyzable GTP analogue, lowered the Ca2+ concentrations required for this contraction and increased the Ca2+ sensitivity of the skinned smooth muscle contraction. GTPγS alone did not induce the contraction in the absence of Ca2+. This GTPγS-enhanced Ca2+ sensitivity was completely abolished by an exoenzyme of Staphylococcus aureus, named EDIN, and an exoenzyme of Clostridium botulinum, named C3, both of which are known to ADP-ribosylate the rho p21 family that belongs to the ras p21-like small GTP-binding protein superfamily. The GTPγS-bound form of rhoA p21 overcame the inhibitory action of EDIN. smg p21B, another small GTP- binding protein, was inactive. EDIN ADP-ribosylated a protein, which was most likely to be rho p21, in the skinned smooth muscle. The GTPγS-bound form of rhoA p21, but not the GDP-bound form, substituted for GTPγS and enhanced the Ca2+ sensitivity of the skinned smooth muscle contraction. smg p21B was inactive. These results indicate that rhoA p21 is involved in the GTPγS- enhanced Ca2+ sensitivity of the smooth muscle contraction.
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M3 - Article
C2 - 1577714
AN - SCOPUS:0026806476
VL - 267
SP - 8719
EP - 8722
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 13
ER -