ISSN:
0886-1544
Keywords:
actin regulatory protein
;
microtubule-associated protein
;
actin bundle
;
microtubule bundle
;
Physarum
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
An F-actin bundling protein was isolated and purified from plasmodium of Physarum polycephalum. The F-actin bundling protein in Physarum extract was passed through a DEAE-cellulose column. After the protein in the fraction was treated with 6 M urea, it was purified by gel filtration on Sephacryl S-300 HR followed by chromatography on CM-Toyopearl (cation exchange) in the presence of 6 M urea. The purified protein gave a single band on SDS-PAGE, and the molecular weight was estimated to be 52,000. This F-actin bundling protein is referred to as the 52 kDa protein.Interestingly, the 52 kDa protein also induced bundling of microtubules. The formation of F-actin and microtubule bundles was Ca2+-insensitive, but depended on the salt concentration. Each bundle formed at NaCl concentrations less than 0.1 M. The 52 kDa protein cross-reacted with monoclonal antibody raised against a HeLa 55 kDa protein (an F-actin bundling protein from HeLa cells) (Yamashiro-Matsumura and Matsumura: J. Biol. Chem. 260:5087-5097, 1985).When the 52 kDa protein was added to a mixture of actin filaments and microtubules, co-bundles composed of both filaments formed. This is the first reported example in which an F-actin bundling protein induced co-bundling of actin filaments and microtubules.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cm.970190403
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