What question did this study set out to answer?

To determine whether phosphorylation of the two heads of nonmuscle thymus myosin occurs randomly or sequentially, and how this phosphorylation governs actin-activated ATPase activity.

July 1, 1985Journal of Biological ChemistryOpen Access

Random phosphorylation of the two heads of thymus myosin and the independent stimulation of their actin-activated ATPases.

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Population

Thymus myosin (monomeric and filamentous) and gizzard myosin light chain kinase

Comparison

Phosphorylation by gizzard myosin light chain… vs Different levels of light chain phosphorylation…

Design

Preclinical

Authors

PWPaul D. WagnerKiel University NVN D VuNational Cancer Institute JGJanet N. GeorgeNational Institute of Dental and Craniofacial Research

Discussion

Member takes

Implication

Thymus myosin heads show independent regulation; challenges smooth muscle models and leaves open cardiac myosin relevance.

Key Points

To determine whether phosphorylation of the two heads of nonmuscle thymus myosin occurs randomly or sequentially, and how this phosphorylation governs actin-activated ATPase activity.
Measured phosphorylation time courses of monomeric and filamentous thymus myosin using gizzard myosin light chain kinase.
Assayed actin-activated ATPase rates across thymus myosin preparations with varying extents of light chain phosphorylation.
Phosphorylation time courses for both monomeric and filamentous thymus myosin fit single exponentials up to greater than 85% completion, demonstrating that both heads phosphorylate at identical rates via a random mechanism.
Stimulation of actin-activated ATPase showed a direct linear correlation with the degree of light chain phosphorylation, establishing that phosphorylation of one head stimulates its ATPase independently of the other head.

Structured PICO

Population

Thymus myosin (monomeric and filamentous) and gizzard myosin light chain kinase

Intervention

Phosphorylation by gizzard myosin light chain kinase

Comparator

Different levels of light chain phosphorylation; comparison with gizzard myosin

Outcome

Time course of phosphorylation and actin-activated ATPase activitysurrogate

This basic science study demonstrates that the two heads of thymus myosin are phosphorylated randomly and their actin-activated ATPases are regulated independently, contrasting with smooth muscle myosin.

Cite This Study

Wagner et al. (1985) studied this question.

synapsesocial.com/papers/6a703a2b5d37378ac1dd5002 https://doi.org/10.1016/s0021-9258(17)39567-4

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Random phosphorylation of the two heads of thymus myosin and the independent stimulation of their actin-activated ATPases.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Random phosphorylation of the two heads of thymus myosin and the independent stimulation of their actin-activated ATPases.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider