Identification of the smooth muscle-specific protein, sm22, as a novel protein kinase C substrate using two-dimensional gel electrophoresis and mass spectrometry

2000 ◽  
Vol 21 (12) ◽  
pp. 2443-2453 ◽  
Author(s):  
Sascha Dammeier ◽  
Josip Lovric ◽  
Manfred Eulitz ◽  
Walter Kolch ◽  
J. Frederic Mushinski ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Gel Electrophoresis ◽  
Specific Protein ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Kinase C ◽  
Novel Protein

Inhibition of myosin light chain phosphatase during Ca(2+)-independent vasocontraction

1993 ◽  
Vol 265 (5) ◽  
pp. C1319-C1324 ◽  
Author(s):  
H. Itoh ◽  
A. Shimomura ◽  
S. Okubo ◽  
K. Ichikawa ◽  
M. Ito ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Water Soluble ◽  
Two Dimensional ◽  
Kinase C ◽  
Rat Thoracic Aorta ◽  
Phosphopeptide Mapping

Phorbol 12,13-dibutyrate (PDB) induced a sustained contraction of rat thoracic aorta strip in Ca(2+)-free buffer without significant change in intracellular free Ca2+ concentration. NKH477, a water-soluble forskolin derivative, markedly relaxed the PDB-induced contraction. The PDB-induced contraction was associated with the phosphorylation of 20-kDa myosin light chain (MLC). Two-dimensional phosphopeptide mapping of 20-kDa MLC revealed that approximately 90% of the phosphopeptides was derived from an MLC kinase-catalyzed reaction and approximately 10% was due to phosphorylation by protein kinase C. NKH477 inhibited the PDB-induced phosphorylation of 20-kDa MLC. MLC phosphatase activity of intact aorta strips was inhibited by the treatment with PDB, and the inhibition was recovered by the application of NKH477. These results suggest that the regulation of MLC phosphatase in vascular smooth muscle may play important roles in the PDB-induced contraction and the NKH477-induced relaxation in Ca(2+)-free buffer.

Acetylcholine Activates Protein Kinase C-α in Pulmonary Venous Smooth Muscle

2007 ◽  
Vol 106 (3) ◽  
pp. 507-514 ◽  
Author(s):  
Xueqin Ding ◽  
Paul A. Murray
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Pulmonary Veins ◽  
Specific Protein ◽  
Isometric Tension ◽  
Kinase C ◽  
Pkc Isoforms ◽  
Pkc Alpha ◽  
Pkc Iota

Background The authors investigated whether acetylcholine-induced contraction in pulmonary venous smooth muscle (PVSM) is associated with the activation of specific protein kinase C (PKC) isoforms. Methods Isolated canine pulmonary venous rings without endothelium were suspended in modified Krebs-Ringer's buffer for measurement of isometric tension. The effects of nonspecific PKC inhibition (bisindolylmaleimide I; 3 x 10 m) and conventional PKC isoform inhibition (Gö7936 10 m) on the acetylcholine dose-response relation were assessed. The expression of conventional PKC isoforms (alpha, beta, gamma), novel PKC isoforms (delta, epsilon, theta), and atypical PKC isoforms (zeta, iota, mu) was measured in PVSM cells by Western blot analysis. The immunofluorescence technique and confocal microscopy were used to localize the cellular distribution of PKC isoforms before and after the addition of acetylcholine. Results Acetylcholine caused dose-dependent contraction in E-pulmonary veins. Pretreatment with bisindolylmaleimide I or Gö7936 attenuated acetylcholine contraction. PKC-alpha, -iota, -mu, and -zeta were expressed, whereas PKC-beta, -gamma, -delta, -epsilon;, and -theta were not expressed in PVSM cells. Immunofluorescence staining for PKC isoforms showed that in unstimulated cells, PKC-alpha and PKC-mu were detected only in the cytoplasm. PKC-iota and PKC-zeta also exhibited a cytoplasmic immunofluorescence pattern, which was especially abundant in the perinuclear zone. Activation with acetylcholine induced translocation of PKC-alpha from cytoplasm to membrane, whereas acetylcholine had no effect on the other PKC isoforms. Translocation of PKC-alpha in response to acetylcholine was blocked by the muscarinic receptor antagonist, atropine. Conclusion Acetylcholine contraction is attenuated by PKC inhibition in PVSM. Acetylcholine induces translocation of PKC-alpha from cytoplasm to membrane in PVSM. These results suggest that PKC-dependent acetylcholine contraction in PVSM may involve activation and translocation of PKC-alpha.

scholarly journals Calponin phosphorylation in vitro and in intact muscle

1993 ◽  
Vol 296 (3) ◽  
pp. 827-836 ◽  
Author(s):  
S J Winder ◽  
B G Allen ◽  
E D Fraser ◽  
H M Kang ◽  
G J Kargacin ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Gel Electrophoresis ◽  
Dependent Protein Kinase ◽  
Kinase C ◽  
Sds Page ◽  
Protein Kinase Ii ◽  
Dependent Protein

Calponin, a thin-filament-associated protein implicated in the regulation of smooth-muscle contraction, is phosphorylated in vitro by protein kinase C and Ca2+/calmodulin-dependent protein kinase II [Winder and Walsh (1990) J. Biol. Chem. 265, 10148-10155] and dephosphorylated by a type 2A protein phosphatase [Winder, Pato and Walsh (1992) Biochem. J. 286, 197-203]. Unphosphorylated calponin binds to actin and inhibits the actin-activated myosin MgATPase; these properties are lost on phosphorylation. Although both serine and threonine residues in calponin are phosphorylated, the major site of phosphorylation by either kinase is Ser-175. Calponin also undergoes phosphorylation when bound to actin in synthetic thin filaments, in a reconstituted actomyosin system, in washed myofibrils and in tissue extracts; this results in dissociation of calponin from actin. Tryptic phosphopeptide mapping indicates that the same sites are phosphorylated in the bound as in the isolated protein. Toad stomach calponin exists in at least three isoforms which differ in charge but exhibit the same molecular mass on SDS/PAGE. In a toad stomach extract, all three isoforms are phosphorylated by protein kinase C or Ca2+/calmodulin-dependent protein kinase II as shown by two-dimensional gel electrophoresis (non-equilibrium pH-gradient gel electrophoresis and SDS/PAGE). Calponin phosphorylation also occurs in intact toad stomach smooth-muscle strips metabolically labelled with 32Pi and stimulated to contract with carbachol. These results support the hypothesis that calponin may be regulated in vivo by phosphorylation-dephosphorylation.

Isoform-specific protein kinase C activity at variable Ca2+ entry during coronary artery contraction by vasoactive eicosanoids

1998 ◽  
Vol 76 (12) ◽  
pp. 1110-1119 ◽  
Author(s):  
Celia A Kanashiro ◽  
Raouf A Khalil
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Coronary Artery ◽  
Protein Kinase ◽  
Calcium Influx ◽  
Surface Membrane ◽  
Smooth Muscle Contraction ◽  
Specific Protein ◽  
Porcine Coronary Artery ◽  
Kinase C

Vasoactive eicosanoids have been implicated in the pathogenesis of coronary vasospasms. The signaling mechanisms of eicosanoid-induced coronary vasoconstriction are unclear, and a role for protein kinase C (PKC) has been suggested. Activated PKC undergoes translocation to the surface membrane in the vicinity of Ca2+ channels; however, the effect of Ca2+ entry on the activity of the specific PKC isoforms in coronary smooth muscle is unknown. In the present study, 45Ca2+ influx and isometric contraction were measured in porcine coronary artery strips incubated at increasing extracellular calcium concentrations ([Ca2+]e) and stimulated with prostaglandin F2α (PGF2α) or the stable thromboxane A2 analog U46619, while in parallel, the cytosolic (C) and particulate (P) fractions were examined for PKC activity and reactivity with anti-PKC antibodies using Western blot analysis. At 0-300 µM [Ca2+]e, both PGF2α and U46619 (10-5 M) significantly increased PKC activity and contraction in the absence of a significant increase in 45Ca2+ influx. At 600 µM [Ca2+]e, PGF2α and U46619 increased P/C PKC activity ratio to a peak of 9.52 and 14.58, respectively, with a significant increase in 45Ca2+ influx and contraction. The 45Ca2+ influx - PKC activity - contraction relationship showed a 45Ca2+-influx threshold of ~7 µmol·kg-1·min-1 for maximal PKC activation by PGF2α and U46619. 45Ca2+ influx > 10 µmol·kg-1·min-1 was associated with further increases in contraction despite a significant decrease in PKC activity. Western blotting analysis revealed α-, δ-, ε-, and ζ-PKC in porcine coronary artery. In unstimulated tissues, α- and ε-PKC were mostly distributed in the cytosolic fraction. Significant eicosanoid-induced translocation of ε-PKC from the cytosolic to the particulate fraction was observed at 0 [Ca2+]e, while translocation of α-PKC was observed at 600 µM [Ca2+]e. Thus, a significant component of eicosanoid-induced coronary contraction is associated with significant PKC activity in the absence of significant increase in Ca2+ entry and may involve activation and translocation of the Ca2+-independent ε-PKC. An additional Ca2+-dependent component of eicosanoid-induced coronary contraction is associated with a peak PKC activity at submaximal Ca2+ entry and may involve activation and translocation of the Ca2+-dependent α-PKC. The results also suggest that a smaller PKC activity at supramaximal Ca2+ entry may be sufficient during eicosanoid-induced contraction of coronary smooth muscle.Key words: protein kinase C, isoform, calcium influx, eicosanoids, vascular smooth muscle, contraction.

Proteome Analysis of CD4+ T Cells Reveals Differentially Expressed Proteins in Infertile Polycystic Ovary Syndrome Patients

2020 ◽  
Vol 20 ◽  
Author(s):  
Fatemeh Nasri ◽  
Maryam Zare ◽  
Mehrnoosh Doroudchi ◽  
Behrouz Gharesi-Fard
Keyword(s):  
Mass Spectrometry ◽  
T Cells ◽  
T Lymphocytes ◽  
Gel Electrophoresis ◽  
Cd4 T Cells ◽  
Polycystic Ovary ◽  
Proteome Analysis ◽  
Two Dimensional ◽  
Ovary Syndrome ◽  
Two Dimensional Gel Electrophoresis

Background: Polycystic ovary syndrome (PCOS) is the most frequent endocrine disorder affecting 6–7% of premenopausal women. Recent studies revealed that the immune system especially CD4+ T helper cells are important in the context PCOS. Proteome analysis of CD4+ T lymphocytes can provide valuable information regarding the biology of these cells in the context of PCOS. Objective: To investigate immune dysregulation in CD4+ T lymphocytes at the protein level in the context of PCOS using two-dimensional gel electrophoresis (2DE) and mass spectrometry (MS). Methods: In the present study, we applied two-dimensional gel electrophoresis / mass spectrometry to identify proteins differentially expressed by peripheral blood CD4+ T cells in ten PCOS women compared with ten healthy women. Western blot technique was used to confirm the identified proteins. Results: Despite the overall proteome similarities, there were significant differences in the expression of seven spots between two groups (P <0.05). Three proteins, namely phosphatidylethanolamine-binding protein 1, proteasome activator complex subunit 1 and triosephosphate isomerase 1 were successfully identified by Mass technique and confirmed by western blot. All characterized proteins were over-expressed in CD4+ T cells from patients compared to CD4+ T cells from controls (P <0.05). In-silico analysis suggested that the over-expressed proteins interact with other proteins involved in cellular metabolism especially glycolysis and ferroptosis pathway. Conclusion: These findings suggest that metabolic adjustments in CD4+ T lymphocytes, which is in favor of increased glycolysis and Th2 differentiation are important in the context of PCOS.

Regulation of Scavenger Receptor Expression in Smooth Muscle Cells by Protein Kinase C

1997 ◽  
Vol 17 (5) ◽  
pp. 969-978 ◽  
Author(s):  
Michele Mietus-Snyder ◽  
Annabelle Friera ◽  
Christopher K. Glass ◽  
Robert E. Pitas
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Smooth Muscle Cells ◽  
Scavenger Receptor ◽  
Muscle Cells ◽  
Receptor Expression ◽  
Kinase C
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