Myosin light chain and heavy chain phosphorylation in smooth muscle: potential regulatory roles for calcium, phospholipids and cyclic nucleotides

1988 ◽  
Vol 16 (4) ◽  
pp. 499-501 ◽  
Author(s):  
DAVID R. HATHAWAY ◽  
LEONARD P. ADAM ◽  
ROBERT C. TURNER ◽  
JOSEPH A. LASH
Keyword(s):  
Smooth Muscle ◽  
Heavy Chain ◽  
Light Chain ◽  
Cyclic Nucleotides ◽  
Myosin Light Chain ◽  
Muscle Potential

Differential expression and effect of 1,25-dihydroxyvitamin D3 on myosin in arterial tree of rats

1995 ◽  
Vol 269 (2) ◽  
pp. C443-C450 ◽  
Author(s):  
K. Ishibashi ◽  
A. Evans ◽  
T. Shingu ◽  
K. Bian ◽  
R. D. Bukoski
Keyword(s):  
Smooth Muscle ◽  
Heavy Chain ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Regulatory Light Chain ◽  
Myosin Regulatory Light Chain ◽  
Arterial Tree ◽  
Dihydroxyvitamin D3 ◽  
1,25 Dihydroxyvitamin D3 ◽  
Wistar Kyoto

The hypothesis that 1,25-dihydroxyvitamin D3 [1,25(OH)2D3, also known as calcitriol] modulates myosin expression in vascular smooth muscle was tested. Wistar-Kyoto or spontaneously hypertensive rats given intraperitoneal injections of 25 ng 1,25(OH)2D3/100 g body weight for varying periods of time showed a greater than twofold increase in aortic mRNA encoding the myosin regulatory light chain relative to 18S rRNA (P < 0.05). 1,25(OH)2D3 administration to Wistar rats caused a significant increase in the aortic content of total myosin regulatory light chain and total myosin heavy chain. The increase in myosin light chain was the result of a specific increase in expression of its smooth muscle isoform [control = 65.2 +/- 3.4% vs. 1,25(OH)2D3 = 78.7 +/- 3.6%, P = 0.020]. 1,25(OH)2D3 had no effect on total myosin light chain or heavy chain in the superior mesenteric artery. The hormone did, however, increase the proportion of the smooth muscle isoform of the light chain in this vessel [control = 81.4 +/- 2.6% vs. 1,25(OH)2D3 = 88.8 +/- 2.1%, P = 0.048]. In branch II and III mesenteric resistance arteries, 1,25(OH)2D3 significantly increased the active stress response to 10 mumol/l norepinephrine but was without effect on total myosin light chain or heavy chain content or on the relative expression of the myosin light chain isoforms [control = 94.0 +/- 1.4% vs. 1,25(OH)2D3 = 95.8 +/- 1.1%, P = 0.33].(ABSTRACT TRUNCATED AT 250 WORDS)

Increased myosin phosphorylation in sensitized canine tracheal smooth muscle

1990 ◽  
Vol 259 (2) ◽  
pp. L53-L56 ◽  
Author(s):  
S. K. Kong ◽  
A. J. Halayko ◽  
N. L. Stephens
Keyword(s):  
Smooth Muscle ◽  
Atpase Activity ◽  
Myosin Heavy Chain ◽  
Airway Smooth Muscle ◽  
Heavy Chain ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Tracheal Smooth Muscle ◽  
Myofibrillar Atpase ◽  
Myofibrillar Atpase Activity

We have reported that the maximal velocity of shortening and myofibrillar adenosine triphosphatase (ATPase) activity of antigen-sensitized airway smooth muscle are higher than that of nonsensitized airway smooth muscle (Kong, S. K., R. P. C. Shiu, and N. L. Stephens. J. Appl. Physiol. 60: 92–94, 1986). To extend these studies, we attempted to determine whether the increased myofibrillar ATPase activity from sensitized airway smooth muscle was associated with either a change in distribution of two myosin heavy chain isozymes or an increase in myosin light chain phosphorylation. Myosin heavy chain isozymes from both control and sensitized airway smooth muscle were separated by 4% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Gels were analyzed by densitometry, which indicated that isozyme band pattern of sensitized airway smooth muscle was not different from that of the control. The maximal levels of phosphorylated myosin light chain from whole cell homogenates of sensitized and control tracheal smooth muscles were 0.65 +/- 0.029 (n = 6) and 0.40 +/- 0.025 mol Pi/mol light chain (n = 6), respectively. The degree of phosphorylation of myosin light chain of sensitized airway smooth muscle was significantly higher than that of the control (P less than 0.05). This study also indicated that increased myofibrillar ATPase activity in sensitized tracheal smooth muscle was correlated with phosphorylation of myosin light chain.

scholarly journals Alterations in expression of myosin and myosin light chain kinases in response to vascular injury

2000 ◽  
Vol 279 (4) ◽  
pp. C1078-C1087 ◽  
Author(s):  
Patricia J. Gallagher ◽  
Yijun Jin ◽  
Gayla Killough ◽  
Emily K. Blue ◽  
Volkhard Lindner
Keyword(s):  
Smooth Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Smooth Muscle Myosin ◽  
Nonmuscle Myosin ◽  
Relative Expression Level ◽  
The Media ◽  
Muscle Myosin

Histochemical analysis of balloon-injured rat carotid arteries revealed a coordinated expression of nonmuscle myosin heavy chain-A and -B (NM-A and NM-B) in response to injury. Expression of these nonmuscle myosin forms shifts from the media to the adventitia and intima. In contrast, expression of smooth muscle myosin heavy chain-1 (SM-1) within the media is not altered, whereas smooth muscle myosin heavy chain-2 (SM-2) expression declines. Western blotting shows a statistically significant increase in expression of NM-A that occurs within 6 h in response to carotid injury, suggesting this myosin form may be an appropriate experimental marker for proliferating, migrating cells in injured vessels. No overall change in the relative expression level of NM-B was detected, suggesting that compensatory declines in media expression are balanced by increases in the intima and adventitia. Expression of SM-1 did not change in response to injury, whereas the expression of SM-2 significantly declined between 24 h and 7 days. Expression of myosin light chain kinase is also negatively regulated, and the decline in its expression parallels downregulation of SM-2.

scholarly journals Arachidonic acid inhibits myosin light chain phosphatase and sensitizes smooth muscle to calcium.

1992 ◽  
Vol 267 (30) ◽  
pp. 21492-21498
Author(s):  
M.C. Gong ◽  
A Fuglsang ◽  
D Alessi ◽  
S Kobayashi ◽  
P Cohen ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Smooth Muscle ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Myosin Light Chain Phosphatase
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