What question did this study set out to answer?

Investigate the molecular mechanisms governing contraction and the assembly-disassembly of thick filaments in permeabilized vertebrate smooth muscle cells.

October 1, 1983The Journal of Cell BiologyOpen Access

Regulation of contraction and thick filament assembly-disassembly in glycerinated vertebrate smooth muscle cells.

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Population

Isolated smooth muscle cells and cell fragments prepared by glycerination and subsequent homogenization

Design

Preclinical

Authors

WCW. Zacheus CandeInstitute of Plant and Microbial Biology, Academia Sinica PTP. ToothMRC Laboratory of Molecular Biology JKJohn Kendrick‐JonesHeart Failure / Cardiomyopathy

Discussion

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Implication

Does not alter clinical management of smooth muscle disorders; leaves open translation of thick filament mechanisms to intact human tissues.

Key Points

Investigate the molecular mechanisms governing contraction and the assembly-disassembly of thick filaments in permeabilized vertebrate smooth muscle cells.
Isolated smooth muscle cells and fragments using glycerination and subsequent homogenization.
Treated cells under varying conditions of calcium, ATP, ATPγS, pH, and trypsin-activated myosin light chain kinase (MLCK).
Reconstituted contraction in depleted cells by sequentially adding gizzard or skeletal myosin, MLCK, calmodulin, troponin, and tropomyosin.
Permeabilized cells contracted to one-third their resting length in the presence of Ca++ and ATP, with Ca++-independent contraction triggered by ATPγS or trypsin-treated MLCK.
In the absence of Ca++, addition of ATP caused rapid detachment and loss of unphosphorylated myosin filaments in an ATP- and pH-dependent manner.
Addition of exogenous gizzard myosin, MLCK, calmodulin, Ca++, and ATP fully restored Ca++-dependent contractile function to extracted cells.

Structured PICO

Population

Isolated smooth muscle cells and cell fragments prepared by glycerination and subsequent homogenization

Intervention

Manipulation of Ca++, ATP, and myosin light chain kinase (MLCK) levels, and addition of gizzard or skeletal myosin

Outcome

Cell contraction and myosin filament assembly/disassemblysurrogate

This basic science study demonstrates that smooth muscle contraction is primarily regulated by thick filaments via MLCK and that myosin filaments are unstable under relaxing conditions.

Cite This Study

Cande et al. (1983) studied this question.

synapsesocial.com/papers/6a843ec77ae632e783bd8384 https://doi.org/10.1083/jcb.97.4.1062

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Implication

Does not alter clinical management of smooth muscle disorders; leaves open translation of thick filament mechanisms to intact human tissues.

Regulation of contraction and thick filament assembly-disassembly in glycerinated vertebrate smooth muscle cells.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Regulation of contraction and thick filament assembly-disassembly in glycerinated vertebrate smooth muscle cells.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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