Expanding role of G proteins in tight junction regulation: Galpha(s) stimulates TJ assembly.

Multiple signaling mechanisms regulate epithelial cell tight junction (TJ) assembly and maintenance. Several G proteins are likely to regulate these processes, but only G(i/o) have been specifically tested. Treatment of MDCK cells with cholera toxin, a Galpha(s) activator, accelerated TJ development in the calcium switch as measured by the time to half-maximal [T(50) (H)] transepithelial resistance (TER). Galpha(s) was predominantly localized in the lateral membrane, but a fraction colocalizes with ZO-1 in the TJ. MDCK cell lines expressing epitope-tagged Galpha(s) and constitutively active (R201Calpha(s)) showed a similar localization. TJ assembly was significantly faster in R201Calpha(s)-MDCK cell lines (T(50) (H) of 1.7 versus 3.3 h for controls) without detectable differences in cAMP levels. Confocal studies showed R201Calpha(s)-MDCK cells more rapidly localized ZO-1 and occludin into the developing TJ without affecting E-cadherin or Na(+)/K(+) ATPase localization. Endogenous Galpha(s) and R201Calpha(s) were immunoprecipitated with ZO-1 at baseline and during TJ assembly. The data supports a model of multiple Galpha subunits interacting with TJ proteins to regulate the assembly and maintenance of the TJ.

[1]  A. Huber,et al.  The Visual G Protein of Fly Photoreceptors Interacts with the PDZ Domain Assembled INAD Signaling Complex via Direct Binding of Activated Gαq to Phospholipase Cβ* , 2000, The Journal of Biological Chemistry.

[2]  M. Itoh,et al.  Direct Binding of Three Tight Junction-Associated Maguks, Zo-1, Zo-2, and Zo-3, with the Cooh Termini of Claudins , 1999, The Journal of cell biology.

[3]  Erika S Wittchen,et al.  Protein Interactions at the Tight Junction , 1999, The Journal of Biological Chemistry.

[4]  J. Anderson,et al.  Transmembrane proteins in the tight junction barrier. , 1999, Journal of the American Society of Nephrology : JASN.

[5]  S. Nigam,et al.  Role of tyrosine phosphorylation in the reassembly of occludin and other tight junction proteins. , 1999, American journal of physiology. Renal physiology.

[6]  M. Itoh,et al.  Characterization of ZO-2 as a MAGUK Family Member Associated with Tight as well as Adherens Junctions with a Binding Affinity to Occludin and α Catenin* , 1999, The Journal of Biological Chemistry.

[7]  James M. Anderson,et al.  The Tight Junction Protein ZO-1 Establishes a Link between the Transmembrane Protein Occludin and the Actin Cytoskeleton* , 1998, The Journal of Biological Chemistry.

[8]  S. Nigam,et al.  Involvement of Gαi2 in the Maintenance and Biogenesis of Epithelial Cell Tight Junctions* , 1998, The Journal of Biological Chemistry.

[9]  L. Rubin,et al.  Microvascular permeability and number of tight junctions are modulated by cAMP. , 1998, American journal of physiology. Heart and circulatory physiology.

[10]  L. Gu,et al.  ZO-3, a Novel Member of the MAGUK Protein Family Found at the Tight Junction, Interacts with ZO-1 and Occludin , 1998, The Journal of cell biology.

[11]  Z. Szallasi,et al.  Protein Kinase C-α Activity Modulates Transepithelial Permeability and Cell Junctions in the LLC-PK1 Epithelial Cell Line* , 1997, The Journal of Biological Chemistry.

[12]  N. Nathanson,et al.  Differential Localization of G-proteins, Gαo and Gαi-1, -2, and -3, in Polarized Epithelial MDCK Cells☆ , 1997 .

[13]  James M. Anderson,et al.  Protein–protein interactions: PDZ domain networks , 1996, Current Biology.

[14]  S. Nigam,et al.  Involvement of a Heterotrimeric G Protein α Subunit in Tight Junction Biogenesis* , 1996, The Journal of Biological Chemistry.

[15]  R. O. Stuart,et al.  Dependence of Epithelial Intercellular Junction Biogenesis on Thapsigargin-sensitive Intracellular Calcium Stores* , 1996, The Journal of Biological Chemistry.

[16]  James M. Anderson,et al.  Cell signalling: MAGUK magic , 1996, Current Biology.

[17]  B. Gumbiner,et al.  Cell Adhesion: The Molecular Basis of Tissue Architecture and Morphogenesis , 1996, Cell.

[18]  B. Kachar,et al.  Identification of Isoforms of G Proteins and PKC that Colocalize with Tight Junctions , 1996, The Journal of Membrane Biology.

[19]  R. O. Stuart,et al.  Regulated assembly of tight junctions by protein kinase C. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[20]  E. Neer.  Heterotrimeric C proteins: Organizers of transmembrane signals , 1995, Cell.

[21]  Michael A. Panichas,et al.  Critical role for intracellular calcium in tight junction biogenesis , 1994, Journal of cellular physiology.

[22]  L. Ercolani,et al.  Targeting of chimeric G alpha i proteins to specific membrane domains. , 1994, Journal of cell science.

[23]  James M. Anderson,et al.  Assembly of the tight junction: the role of diacylglycerol , 1993, The Journal of cell biology.

[24]  J. Anderson,et al.  ZO-1 maintains its spatial distribution but dissociates from junctional fibrils during tight junction regulation. , 1993, The American journal of physiology.

[25]  K. Simons,et al.  Regulation of apical transport in epithelial cells by a Gsclass of heterotrimeric G protein , 1993, Nature.

[26]  J. Gallardo,et al.  The making of a tight junction , 1993, Journal of Cell Science.

[27]  H. Bourne,et al.  Activation of the alpha subunit of Gs in intact cells alters its abundance, rate of degradation, and membrane avidity , 1992, The Journal of cell biology.

[28]  E. Rodriguez-Boulan,et al.  Changes in intracellular calcium during the development of epithelial polarity and junctions. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[29]  N. Narula,et al.  A heterotrimeric G protein, G alpha i-3, on Golgi membranes regulates the secretion of a heparan sulfate proteoglycan in LLC-PK1 epithelial cells , 1991, The Journal of cell biology.

[30]  E. Rodriguez-Boulan,et al.  Morphogenesis of the polarized epithelial cell phenotype. , 1989, Science.

[31]  B. Gumbiner,et al.  A functional assay for proteins involved in establishing an epithelial occluding barrier: identification of a uvomorulin-like polypeptide , 1986, The Journal of cell biology.

[32]  L. Brunton,et al.  Compartments of cyclic AMP and protein kinase in mammalian cardiomyocytes. , 1983, The Journal of biological chemistry.

[33]  K. Catt,et al.  Actions of choleragen and gonadotropin in isolated Leydig cells. Functional compartmentalization of the hormone-activated cyclic AMP response. , 1978, The Journal of biological chemistry.

[34]  M. Field.  Intestinal secretion: effect of cyclic AMP and its role in cholera. , 1971 .

[35]  J. Madara.  Regulation of the movement of solutes across tight junctions. , 1998, Annual review of physiology.

[36]  S. Nigam,et al.  Molecular structure and assembly of the tight junction. , 1998, American journal of physiology. Renal physiology.