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Nonmuscle Myosin motor of smooth muscle.

Löfgren, Mia; Ekblad, Eva LU ; Morano, Ingo and Arner, Anders LU (2003) In Journal of General Physiology 121(4). p.301-310
Abstract
Nonmuscle myosin can generate force and shortening in smooth muscle, as revealed by studies of the urinary bladder from mice lacking smooth muscle myosin heavy chain (SM-MHC) but expressing the nonmuscle myosin heavy chains A and B (NM-MHC A and B; Morano, I., G.X. Chai, L.G. Baltas, V. Lamounier-Zepter, G. Lutsch, M. Kott, H. Haase, and M. Bader. 2000. Nat. Cell Biol. 2:371–375). Intracellular calcium was measured in urinary bladders from SM-MHC–deficient and SM-MHC–expressing mice in relaxed and contracted states. Similar intracellular [Ca2+] transients were observed in the two types of preparations, although the contraction of SM-MHC–deficient bladders was slow and lacked an initial peak in force. The difference in contraction kinetics... (More)
Nonmuscle myosin can generate force and shortening in smooth muscle, as revealed by studies of the urinary bladder from mice lacking smooth muscle myosin heavy chain (SM-MHC) but expressing the nonmuscle myosin heavy chains A and B (NM-MHC A and B; Morano, I., G.X. Chai, L.G. Baltas, V. Lamounier-Zepter, G. Lutsch, M. Kott, H. Haase, and M. Bader. 2000. Nat. Cell Biol. 2:371–375). Intracellular calcium was measured in urinary bladders from SM-MHC–deficient and SM-MHC–expressing mice in relaxed and contracted states. Similar intracellular [Ca2+] transients were observed in the two types of preparations, although the contraction of SM-MHC–deficient bladders was slow and lacked an initial peak in force. The difference in contraction kinetics thus do not reflect differences in calcium handling. Thick filaments were identified with electron microscopy in smooth muscle cells of SM-MHC–deficient bladders, showing that NM-MHC can form filaments in smooth muscle cells. Maximal shortening velocity of maximally activated, skinned smooth muscle preparations from SM-MHC–deficient mice was significantly lower and more sensitive to increased MgADP compared with velocity of SM-MHC–expressing preparations. Active force was significantly lower and less inhibited by increased inorganic phosphate. In conclusion, large differences in nucleotide and phosphate binding exist between smooth and nonmuscle myosins. High ADP binding and low phosphate dependence of nonmuscle myosin would influence both velocity of actin translocation and force generation to promote slow motility and economical force maintenance of the cell. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
ATP, urinary bladder, nonmuscle myosin, ADP, phosphate
in
Journal of General Physiology
volume
121
issue
4
pages
301 - 310
publisher
Rockefeller Institute for Medical Research
external identifiers
  • wos:000182141100004
  • pmid:12668734
  • scopus:0037388579
ISSN
0022-1295
DOI
10.1085/jgp.200208720
language
English
LU publication?
yes
id
c6339c45-7a8c-4cd1-a9a9-93f662a8ec0a (old id 113637)
date added to LUP
2007-07-17 11:24:53
date last changed
2018-01-07 08:42:09
@article{c6339c45-7a8c-4cd1-a9a9-93f662a8ec0a,
  abstract     = {Nonmuscle myosin can generate force and shortening in smooth muscle, as revealed by studies of the urinary bladder from mice lacking smooth muscle myosin heavy chain (SM-MHC) but expressing the nonmuscle myosin heavy chains A and B (NM-MHC A and B; Morano, I., G.X. Chai, L.G. Baltas, V. Lamounier-Zepter, G. Lutsch, M. Kott, H. Haase, and M. Bader. 2000. Nat. Cell Biol. 2:371–375). Intracellular calcium was measured in urinary bladders from SM-MHC–deficient and SM-MHC–expressing mice in relaxed and contracted states. Similar intracellular [Ca2+] transients were observed in the two types of preparations, although the contraction of SM-MHC–deficient bladders was slow and lacked an initial peak in force. The difference in contraction kinetics thus do not reflect differences in calcium handling. Thick filaments were identified with electron microscopy in smooth muscle cells of SM-MHC–deficient bladders, showing that NM-MHC can form filaments in smooth muscle cells. Maximal shortening velocity of maximally activated, skinned smooth muscle preparations from SM-MHC–deficient mice was significantly lower and more sensitive to increased MgADP compared with velocity of SM-MHC–expressing preparations. Active force was significantly lower and less inhibited by increased inorganic phosphate. In conclusion, large differences in nucleotide and phosphate binding exist between smooth and nonmuscle myosins. High ADP binding and low phosphate dependence of nonmuscle myosin would influence both velocity of actin translocation and force generation to promote slow motility and economical force maintenance of the cell.},
  author       = {Löfgren, Mia and Ekblad, Eva and Morano, Ingo and Arner, Anders},
  issn         = {0022-1295},
  keyword      = {ATP,urinary bladder,nonmuscle myosin,ADP,phosphate},
  language     = {eng},
  number       = {4},
  pages        = {301--310},
  publisher    = {Rockefeller Institute for Medical Research},
  series       = {Journal of General Physiology},
  title        = {Nonmuscle Myosin motor of smooth muscle.},
  url          = {http://dx.doi.org/10.1085/jgp.200208720},
  volume       = {121},
  year         = {2003},
}