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Research Database PMU-SQQUID

UNC-87 is an actin-bundling protein.
Kranewitter, WJ; Ylanne, J; Gimona, M;
J Biol Chem. 2001; 276(9): 6306-6312.
Originalarbeiten (Zeitschrift)


Gimona Mario


The Caenorhabditis elegans unc-87 gene product is essential for the maintenance of the nematode body wall muscle where it is found colocalized with actin in the I band. The molecular domain structure of the protein reveals similarity to the C-terminal repeat region of the smooth muscle actin-binding protein calponin. In this study we investigated the in vitro function of UNC-87 using both the full-length recombinant molecule and several truncated mutants. According to analytical ultracentrifugation UNC-87 occurs as a monomer in solution. UNC-87 cosedimented with both smooth and skeletal muscle F-actin, but not with monomeric G-actin, and exhibited potent actin filament bundling activity. Actin binding was independent of the presence of tropomyosin and the actin cross-linking proteins filamin and cu-actinin. Consistent with its actin bundling activity in vitro, UNC-87 tagged with green fluorescent protein associated with and promoted the formation of actin stress fiber bundles in living cells. These data identify UNC-87 as an actin-bundling protein and highlight the calponin-like repeats as a novel actin-binding module.

Useful keywords (using NLM MeSH Indexing)



Base Sequence

Caenorhabditis elegans Proteins*

Cells, Cultured

Helminth Proteins/chemistry*

Helminth Proteins/isolation*


Helminth Proteins/physiology

Molecular Sequence Data

Muscle Proteins/chemistry*

Muscle Proteins/isolation*


Muscle Proteins/physiology


Recombinant Proteins/isolation*


Repetitive Sequences, Amino Acid