scholarly journals Phosphorylation of Zona Occludens-2 by Protein Kinase Cε Regulates Its Nuclear Exportation

2009 ◽  
Vol 20 (18) ◽  
pp. 4120-4129 ◽  
Author(s):  
David Chamorro ◽  
Lourdes Alarcón ◽  
Arturo Ponce ◽  
Rocio Tapia ◽  
Héctor González-Aguilar ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase ◽  
Nuclear Export ◽  
Phosphorylation Site ◽  
Putative Protein ◽  
Kinase C ◽  
Junction Protein ◽  
Zona Occludens ◽  
Intracellular Fate ◽  
Putative Protein Kinase

Here, we have analyzed the subcellular destiny of newly synthesized tight junction protein zona occludens (ZO)-2. After transfection in sparse cells, 74% of cells exhibit ZO-2 at the nucleus, and after 18 h the value decreases to 17%. The mutation S369A located within the nuclear exportation signal 1 of ZO-2 impairs the nuclear export of the protein. Because Ser369 represents a putative protein kinase C (PKC) phosphorylation site, we tested the effect of PKC inhibition and stimulation on the nuclear export of ZO-2. Our results strongly suggest that the departure of ZO-2 from the nucleus is regulated by phosphorylation at Ser369 by novel PKCε. To test the route taken by ZO-2 from synthesis to the plasma membrane, we devised a novel nuclear microinjection assay in which the nucleus served as a reservoir for anti-ZO-2 antibody. Through this assay, we demonstrate that a significant amount of newly synthesized ZO-2 goes into the nucleus and is later relocated to the plasma membrane. These results constitute novel information for understanding the mechanisms that regulate the intracellular fate of ZO-2.

scholarly journals The Acidic Region and Conserved Putative Protein Kinase C Phosphorylation Site in Nef Are Important for SIV Replication in Rhesus Macaques

Virology ◽  
1999 ◽  
Vol 257 (1) ◽  
pp. 138-155 ◽  
Author(s):  
Silke Carl ◽  
A.John Iafrate ◽  
Sabine M. Lang ◽  
Christiane Stahl-Hennig ◽  
Eva M. Kuhn ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Rhesus Macaques ◽  
Phosphorylation Site ◽  
Putative Protein ◽  
Kinase C ◽  
Acidic Region ◽  
Putative Protein Kinase

Testase 1 (ADAM 24) a plasma membrane-anchored sperm protease implicated in sperm function during epididymal maturation or fertilization

2001 ◽  
Vol 114 (9) ◽  
pp. 1787-1794 ◽  
Author(s):  
G.Z. Zhu ◽  
D.G. Myles ◽  
P. Primakoff
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Acrosome Reaction ◽  
Phosphorylation Site ◽  
Equatorial Region ◽  
Proteolytic Processing ◽  
Mature Sperm ◽  
Kinase C

Plasma membrane-anchored proteases have key roles in cell signaling, migration and refashioning the cell surface and its surroundings. We report the first example of a plasma membrane-anchored protease on mature sperm, testase 1 (ADAM 24). Unlike other studied sperm ADAMs (fertilin (α) and (β), cyritestin) whose metalloprotease domains are removed during sperm development, we found testase 1 retains an active metalloprotease domain, suggesting it acts as a protease on mature sperm. Testase 1 is a glycoprotein (molecular mass 88 kDa), localized to the equatorial region of the plasma membrane of cauda epididymal sperm. Typically, proteolytic removal of the pro-domain is an initial activation step for ADAM proteases. The pro-domain of the testase 1 precursor (108 kDa) is proteolytically removed as sperm transit the caput epididymis to produce processed (mature) testase 1 (88 kDa). Testase 1 is unique among all studied ADAMs in that its proteolytic processing occurs on the sperm plasma membrane instead of at an intracellular site (the Golgi). Using GST-fusion proteins and a synthetic testase 1 C-terminal peptide, we found that the cytoplasmic tail of testase 1 could be phosphorylated in vitro by protein kinase C (PKC). Thus testase 1 apparently has a cytoplasmic PKC phosphorylation site(s). Protein kinase C is known to stimulate other ADAMs' protease activity. Because events of the acrosome reaction include PKC activation, we speculate that testase 1 protease function could be important in sperm penetration of the zona pellucida after sperm PKC is activated during the acrosome reaction.

Differential effects of putative protein kinase C inhibitors on contraction of rat aortic smooth muscle

1993 ◽  
Vol 264 (4) ◽  
pp. H1300-H1306 ◽  
Author(s):  
Y. Shimamoto ◽  
H. Shimamoto ◽  
C. Y. Kwan ◽  
E. E. Daniel
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinases ◽  
Induced Response ◽  
Dependent Manner ◽  
Contractile Responses ◽  
Putative Protein ◽  
Calphostin C ◽  
Kinase C ◽  
Putative Protein Kinase

We investigated effects of three kinds of putative protein kinase C (PKC) inhibitors, calphostin C, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7), and stauro-sporine, on aortic muscle contractions induced by KCl, phenylephrine, 12-O-tetradecanoylphorbol-13-acetate (TPA), and phorbol 12, 13-dibutyrate (PDBu). Calphostin C noncompetitively inhibited TPA-induced contractions in a concentration-dependent manner. At 10(-6) M, calphostin C completely abolished responses to TPA and also effectively inhibited PDBu-induced contractions. Such a concentration of calphostin C had no effect on KCl-induced contractions but decreased the maximal tension of phenylephrine-induced response curve by 35.3 +/- 6.6% H-7 (10(-5) M had little effect on TPA-induced contraction but significantly inhibited contractile responses to phenylephrine and KCl. Staurosporine (10(-8) M, 3 x 10(-8) M) inhibited contractile responses to KCl, phenylephrine, and TPA. We suggest that staurosporine and H-7, which are known to act on the catalytic domain of PKC carrying high degree of sequence homology with other protein kinases, are relatively nonselective for PKC. On the other hand, calphostin C acting on the regulatory domain of PKC, which is distinct from other protein kinases, may serve as a relatively more selective PKC inhibitor.

scholarly journals Phospholipase C-eta Enzymes as Putative Protein Kinase C and Ca2+ Signalling Components in Neuronal and Neuroendocrine Tissues

2007 ◽  
Vol 86 (4) ◽  
pp. 243-248 ◽  
Author(s):  
Alan J. Stewart ◽  
Kevin Morgan ◽  
Colin Farquharson ◽  
Robert P. Millar
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Putative Protein ◽  
Kinase C ◽  
Putative Protein Kinase

Role of a geminivirus AV2 protein putative protein kinase C motif on subcellular localization and pathogenicity

2008 ◽  
Vol 135 (1) ◽  
pp. 115-124 ◽  
Author(s):  
R.V. Chowda-Reddy ◽  
Fidelis Achenjang ◽  
Christian Felton ◽  
Marie T. Etarock ◽  
Marie-Therese Anangfac ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Subcellular Localization ◽  
Putative Protein ◽  
Kinase C ◽  
Putative Protein Kinase

scholarly journals The intracellular fate of zonula occludens 2 is regulated by the phosphorylation of SR repeats and the phosphorylation/O-GlcNAcylation of S257

2013 ◽  
Vol 24 (16) ◽  
pp. 2528-2543 ◽  
Author(s):  
Miguel Quiros ◽  
Lourdes Alarcón ◽  
Arturo Ponce ◽  
Thomas Giannakouros ◽  
Lorenza González-Mariscal
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase ◽  
Posttranslational Modifications ◽  
Proliferating Cells ◽  
Akt Activation ◽  
Dual Localization ◽  
Epidermal Growth ◽  
Proteosomal Degradation ◽  
Zona Occludens ◽  
Intracellular Fate

Zona occludens 2 (ZO-2) has a dual localization. In confluent epithelia, ZO-2 is present at tight junctions (TJs), whereas in sparse proliferating cells it is also found at the nucleus. Previously we demonstrated that in sparse cultures, newly synthesized ZO-2 travels to the nucleus before reaching the plasma membrane. Now we find that in confluent cultures newly synthesized ZO-2 goes directly to the plasma membrane. Epidermal growth factor induces through AKT activation the phosphorylation of the kinase for SR repeats, serine arginine protein kinase 1, which in turn phosphorylates ZO-2, which contains 16 SR repeats. This phosphorylation induces ZO-2 entry into the nucleus and accumulation in speckles. ZO-2 departure from the nucleus requires intact S257, and stabilizing the β-O-linked N-acetylglucosylation (O-GlcNAc) of S257 with O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino-N-phenylcarbamate, an inhibitor of O-GlcNAcase, triggers nuclear exportation and proteosomal degradation of ZO-2. At the plasma membrane ZO-2 is not O-GlcNAc, and instead, as TJs mature, it becomes phosphorylated at S257 by protein kinase Cζ. This late phosphorylation of S257 is required for the correct cytoarchitecture to develop, as cells transfected with ZO-2 mutant S257A or S257E form aberrant cysts with multiple lumens. These results reveal novel posttranslational modifications of ZO-2 that regulate the intracellular fate of this protein.

scholarly journals Phosphoinositide-Dependent Phosphorylation of PDK1 Regulates Nuclear Translocation

2005 ◽  
Vol 25 (6) ◽  
pp. 2347-2363 ◽  
Author(s):  
Michael P. Scheid ◽  
Michael Parsons ◽  
James R. Woodgett
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase ◽  
Posttranslational Modifications ◽  
Nuclear Export ◽  
Nuclear Translocation ◽  
Pleckstrin Homology Domain ◽  
Subcellular Trafficking ◽  
Kinase C ◽  
Ribosomal S6 Kinase ◽  
Nuclear Shuttling

ABSTRACT 3-Phosphoinositide-dependent kinase 1 (PDK1) phosphorylates the activation loop of a number of protein serine/threonine kinases of the AGC kinase superfamily, including protein kinase B (PKB; also called Akt), serum and glucocorticoid-induced kinase, protein kinase C isoforms, and the p70 ribosomal S6 kinase. PDK1 contains a carboxyl-terminal pleckstrin homology domain, which targets phosphoinositide lipids at the plasma membrane and is central to the activation of PKB. However, PDK1 subcellular trafficking to other compartments is not well understood. We monitored the posttranslational modifications of PDK1 following insulin-like growth factor 1 stimulation. PDK1 underwent rapid and transient phosphorylation on S396, which was dependent upon plasma membrane localization. Phosphorylation of S396 was necessary for nuclear shuttling of PDK1, possibly through its influence on an adjacent nuclear export sequence. Thus, mitogen-stimulated phosphorylation of PDK1 provides a means for directed PDK1 subcellular trafficking, with potential implications for PDK1 signaling.

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