TY - JOUR
T1 - G Protein β Subunit Types Differentially Interact with a Muscarinic Receptor but Not Adenylyl Cyclase Type II or Phospholipase C-β2/3
AU - Hou, Yongmin
AU - Chang, Vanessa
AU - Capper, Austin B.
AU - Taussig, Ronald
AU - Gautam, N.
PY - 2001/6/8
Y1 - 2001/6/8
N2 - In comparison with the α subunit of G proteins, the role of the β subunit in signaling is less well understood. During the regulation of effectors by the βγ complex, it is known that the β subunit contacts effectors directly, whereas the role of the β subunit is undefined in receptor-G protein interaction. Among the five G protein β subunits known, the β4 subunit type is the least studied. We compared the ability of βγ complexes containing β4 and the well characterized β1 to stimulate three different effectors: phospholipase C-β2, phospholipase C-β3, and adenylyl cyclase type II. β 4γ2 and β1γ2 activated all three of these effectors with equal efficacy. However, nucleotide exchange in a G protein constituting αoβ 4γ2 was stimulated significantly more by the M2 muscarinic receptor compared with αoβ1γ 2. Because αo forms heterotrimers with β 4γ2 and β1γ2 equally well, these results show that the β subunit type plays a direct role in the receptor activation of a G protein.
AB - In comparison with the α subunit of G proteins, the role of the β subunit in signaling is less well understood. During the regulation of effectors by the βγ complex, it is known that the β subunit contacts effectors directly, whereas the role of the β subunit is undefined in receptor-G protein interaction. Among the five G protein β subunits known, the β4 subunit type is the least studied. We compared the ability of βγ complexes containing β4 and the well characterized β1 to stimulate three different effectors: phospholipase C-β2, phospholipase C-β3, and adenylyl cyclase type II. β 4γ2 and β1γ2 activated all three of these effectors with equal efficacy. However, nucleotide exchange in a G protein constituting αoβ 4γ2 was stimulated significantly more by the M2 muscarinic receptor compared with αoβ1γ 2. Because αo forms heterotrimers with β 4γ2 and β1γ2 equally well, these results show that the β subunit type plays a direct role in the receptor activation of a G protein.
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U2 - 10.1074/jbc.M010424200
DO - 10.1074/jbc.M010424200
M3 - Article
C2 - 11262394
AN - SCOPUS:0035827658
SN - 0021-9258
VL - 276
SP - 19982
EP - 19988
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 23
ER -