G protein coupling to M1 and M3 muscarinic receptors in sublingual glands.

Rat sublingual gland M2 and M3 muscarinic receptors each directly activate exocrine secretion. To investigate the functional role of coreceptor expression, we determined receptor-G protein coupling. Although membrane proteins of 40 and 41 kDa are ADP-ribosylated by pertussis toxin (PTX), and 44 kDa proteins by cholera toxin (CTX), both carbachol-stimulated high-affinity GTPase activity and the GTP-induced shift in agonist binding are insensitive to CTX or PTX. Carbachol enhances photoaffinity labeling ([alpha-(32)P]GTP-azidoaniline) of only 42-kDa proteins that are subsequently tractable to immunoprecipitation by antibodies specific for Galpha(q) or Galpha(11) but not Galpha(12) or Galpha(13). Carbachol-stimulated photoaffinity labeling as well as phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis is reduced 55% and 60%, respectively, by M1 receptor blockade with m1-toxin. Galpha(q/11)-specific antibody blocks carbachol-stimulated PIP2 hydrolysis. We also provide estimates of the molar ratios of receptors to Galpha(q) and Galpha(11). Although simultaneous activation of M1 and M3 receptors is required for a maximal response, both receptor subtypes are coupled to Galpha(q) and Galpha(11) to stimulate exocrine secretion via redundant mechanisms.

[1]  C. Buckmaster,et al.  A Rho Exchange Factor Mediates Thrombin and Gα12-induced Cytoskeletal Responses* , 1999, The Journal of Biological Chemistry.

[2]  L. Latchney,et al.  Both M1 and M3 receptors regulate exocrine secretion by mucous acini. , 1996, The American journal of physiology.

[3]  P. Abel,et al.  Identification of muscarinic receptor subtypes in mouse parotid gland. , 1996, The American journal of physiology.

[4]  N. Dhanasekaran,et al.  Signaling by the G12 class of G proteins. , 1996, Cellular signalling.

[5]  A. Smrcka,et al.  Identification of a phospholipase C beta2 region that interacts with Gbeta-gamma. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[6]  T. Gudermann,et al.  Diversity and selectivity of receptor-G protein interaction. , 1996, Annual review of pharmacology and toxicology.

[7]  G. Roth,et al.  Decreased m3-Muscarinic and α1-Adrenergic Receptor Stimulation of PIP2 Hydrolysis in Parotid Gland Membranes from Aged Rats: Defect in Activation of Gαq/11 , 1995 .

[8]  C. Felder.  Muscarinic acetylcholine receptors: signal transduction through multiple effectors , 1995, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[9]  P. Casey,et al.  Subtype-specific binding of azidoanilido-GTP by purified G protein alpha subunits. , 1994, Biochemistry.

[10]  T. Wieland,et al.  Transfected muscarinic acetylcholine receptors selectively couple to Gi-type G proteins and Gq/11. , 1994, Molecular pharmacology.

[11]  G. Schultz,et al.  G12 and G13 alpha-subunits are immunochemically detectable in most membranes of various mammalian cells and tissues. , 1994, Biochemical and biophysical research communications.

[12]  D. Culp,et al.  Muscarinic cholinergic receptor subtypes in rat sublingual glands. , 1994, The American journal of physiology.

[13]  T. Bonner,et al.  Differential activation of inositol 1,4,5-trisphosphate-sensitive calcium pools by muscarinic receptors in Xenopus laevis oocytes. , 1993, Cell calcium.

[14]  L. Latchney,et al.  Mucinlike glycoproteins from cat tracheal gland cells in primary culture. , 1993, The American journal of physiology.

[15]  B. Baum,et al.  Principles of Saliva Secretion , 1993, Annals of the New York Academy of Sciences.

[16]  M. Simon,et al.  Purification from Sf9 cells and characterization of recombinant Gq alpha and G11 alpha. Activation of purified phospholipase C isozymes by G alpha subunits. , 1993, The Journal of biological chemistry.

[17]  J. E. Melvin,et al.  Membrane potential regulates Ca2+ uptake and inositol phosphate generation in rat sublingual mucous acini. , 1993, Cell calcium.

[18]  B. Schlegel,et al.  Analysis of Gz alpha by site-directed mutagenesis. Sites and specificity of protein kinase C-dependent phosphorylation. , 1993, The Journal of biological chemistry.

[19]  M. Simon,et al.  The G alpha q and G alpha 11 proteins couple the thyrotropin-releasing hormone receptor to phospholipase C in GH3 rat pituitary cells. , 1992, The Journal of biological chemistry.

[20]  R. Oswald,et al.  The Interaction of a Kainate Receptor from Goldfish Brain with a Pertussis Toxin‐Sensitive GTP Binding Protein , 1991, Annals of the New York Academy of Sciences.

[21]  J. E. Melvin,et al.  A capacitative Ca2+ influx is required for sustained fluid secretion in sublingual mucous acini. , 1991, The American journal of physiology.

[22]  B. Baum,et al.  Evidence that M3 muscarinic receptors in rat parotid gland couple to two second messenger systems. , 1991, The American journal of physiology.

[23]  M. Simon,et al.  Characterization of G-protein alpha subunits in the Gq class: expression in murine tissues and in stromal and hematopoietic cell lines. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[24]  M. Simon,et al.  Antibodies to the αq subfamily of guanine nucleotide-binding regulatory protein α subunits attenuate activation of phosphatidylinositol 4,5-bisphosphate hydrolysis by hormones , 1991 .

[25]  A. Hand,et al.  Rat sublingual gland as a model to study glandular mucous cell secretion. , 1991, The American journal of physiology.

[26]  P. Sternweis,et al.  Purification of unique alpha subunits of GTP-binding regulatory proteins (G proteins) by affinity chromatography with immobilized beta gamma subunits. , 1990, The Journal of biological chemistry.

[27]  W. Hoss,et al.  Differential coupling between muscarinic receptors and G-proteins in regions of the rat brain. , 1990, Biochemical pharmacology.

[28]  N. Birdsall,et al.  Muscarinic receptor subtypes. , 1990, Annual review of pharmacology and toxicology.

[29]  M. Simon,et al.  Characterization of G-protein a subunits in the Gq class : Expression in murine tissues and in stromal and hematopoietic cell lines ( heterotrimeric GTP-binding protein / signal transduction / multigene family / phospholipase C ) , 2022 .