scholarly journals Calcium ion influx during mitogenic stimulation of lymphocytes.

1987 ◽  
Vol 12 (4) ◽  
pp. 345-355 ◽  
Author(s):  
Hiroshi Komada ◽  
Hiroshi Nakabayashi ◽  
Hiroshi Nakano ◽  
Hideki Takanari ◽  
Takao Takahashi ◽  
...  
Keyword(s):  
Calcium Ion ◽  
Mitogenic Stimulation ◽  
Ion Influx ◽  
Stimulation Of

scholarly journals Phosphorylation by Cyclin C/Cyclin-Dependent Kinase 2 following Mitogenic Stimulation of Murine Fibroblasts Inhibits Transcriptional Activity of LSF during G1 Progression

2009 ◽  
Vol 29 (9) ◽  
pp. 2335-2345 ◽  
Author(s):  
Utsav H. Saxena ◽  
Christina M. H. Powell ◽  
Jill K. Fecko ◽  
Roxanne Cacioppo ◽  
Hubert S. Chou ◽  
...  
Keyword(s):  
Transcriptional Activity ◽  
Target Genes ◽  
Cyclin Dependent Kinase ◽  
Mitogenic Stimulation ◽  
Mouse Fibroblasts ◽  
Cyclin C ◽  
Murine Fibroblasts ◽  
Interfering Rna ◽  
Stimulation Of

ABSTRACT Transcription factor LSF is required for progression from quiescence through the cell cycle, regulating thymidylate synthase (Tyms) expression at the G1/S boundary. Given the constant level of LSF protein from G0 through S, we investigated whether LSF is regulated by phosphorylation in G1. In vitro, LSF is phosphorylated by cyclin E/cyclin-dependent kinase 2 (CDK2), cyclin C/CDK2, and cyclin C/CDK3, predominantly on S309. Phosphorylation of LSF on S309 is maximal 1 to 2 h after mitogenic stimulation of quiescent mouse fibroblasts. This phosphorylation is mediated by cyclin C-dependent kinases, as shown by coimmunoprecipitation of LSF and cyclin C in early G1 and by abrogation of LSF S309 phosphorylation upon suppression of cyclin C with short interfering RNA. Although mouse fibroblasts lack functional CDK3 (the partner of cyclin C in early G1 in human cells), CDK2 compensates for this absence. By transient transfection assays, phosphorylation at S309, mediated by cyclin C overexpression, inhibits LSF transactivation. Moreover, overexpression of cyclin C and CDK3 inhibits induction of endogenous Tyms expression at the G1/S transition. These results identify LSF as only the second known target (in addition to pRb) of cyclin C/CDK activity during progression from quiescence to early G1. Unexpectedly, this phosphorylation prevents induction of LSF target genes until late G1.

Effect of calcium on neurohumoral stimulation of feline colonic smooth muscle

1982 ◽  
Vol 243 (2) ◽  
pp. G134-G140
Author(s):  
W. J. Snape
Keyword(s):  
Smooth Muscle ◽  
Spike Activity ◽  
Calcium Ion ◽  
Calcium Concentration ◽  
Extracellular Calcium ◽  
Ion Concentration ◽  
Myoelectric Activity ◽  
Ionic Calcium ◽  
Calcium Ion Concentration ◽  
Stimulation Of

The purpose of this study was to compare the effect of altering the extracellular calcium ion concentration on bethanechol or octapeptide of cholecystokinin (OP-CCK) stimulation of the isolated transverse colon of the cat. Myoelectric activity was recorded with monopolar glass-pore electrodes. Bethanechol (10(-6) M) stimulated an increase in the number of slow waves with superimposed spike potentials to 85.5 +/- 5.3% (P less than 0.001) compared with the basal spike activity (8.9 +/- 1.4%). OP-CCK (4 x 10(-9)) also increased spike activity (80.7 +/- 3.8%, P less than 0.001), which was not inhibited by atropine, phentolamine, or propranolol. Addition of 0.0 mM calcium solution to the colonic smooth muscle abolished both slow-wave and spike activity, which returned after replacing 0.25 mM calcium in the solution. Bethanechol stimulated a greater increase in spike activity as the concentration of calcium was increased. OP-CCK stimulation of colonic spike activity was more sensitive to the extracellular calcium concentration than bethanechol stimulation. Verapamil had a minimal effect on bethanechol stimulation of colonic spike activity, but it inhibited the OP-CCK stimulation. These studies suggest that 1) OP-CCK appears to stimulate colonic smooth muscle directly and 2) OP-CCK requires the presence of a greater amount of extracellular ionic calcium in order to stimulate colonic spike activity compared with bethanechol.

Are capacitation or calcium ion influx required for the human sperm acrosome reaction?

1994 ◽  
Vol 62 (6) ◽  
pp. 1255-1261 ◽  
Author(s):  
Peter Bielfeld ◽  
Robert A. Anderson ◽  
Steven R. Mack ◽  
Christopher J. De Jonge ◽  
Lourens J.D. Zaneveld
Keyword(s):  
Calcium Ion ◽  
Acrosome Reaction ◽  
Human Sperm ◽  
Ion Influx ◽  
Sperm Acrosome Reaction ◽  
Sperm Acrosome

scholarly journals Identification of a Murine TEF-1-related Gene Expressed after Mitogenic Stimulation of Quiescent Fibroblasts and during Myogenic Differentiation

1996 ◽  
Vol 271 (23) ◽  
pp. 13786-13795 ◽  
Author(s):  
Debbie K. W. Hsu ◽  
Yan Guo ◽  
Gregory F. Alberts ◽  
Neal G. Copeland ◽  
Debra J. Gilbert ◽  
...  
Keyword(s):  
Myogenic Differentiation ◽  
Related Gene ◽  
Mitogenic Stimulation ◽  
Stimulation Of
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