ISSN:
0192-253X
Keywords:
Dictyostelium
;
filopodia
;
actin binding proteins
;
calcium
;
cell motility
;
Life and Medical Sciences
;
Genetics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
The Dictyostelium discoideum 30,000 dalton actin-binding protein is an actin cross-linking protein that organizes formation of parallel bundles of actin filaments in vitro, and is present in filopodia in living cells. This protein binds calcium directly and exhibits a decreased affinity for actin filaments in the presence of micromolar calcium. In this work, the existence of antigenic homologs of the 30,000 dalton protein in Physarum polycephalum, Schistosoma mansoni, Chara carolina, and Drosophila melanogaster is detected by use of affinity purified antibody and electrophoretic blotting methods. The expression of this protein during development of Dictyostelium is also analyzed, revealing a progressive 3-fold decrease in the level of this protein in amoebae between the vegetative and slug stages. A highly ordered structure of bundles of actin and the 30,000 dalton protein formed in vitro is inferred from the presence of transverse striations on the bundles with a minor periodicity at 11.4 nm and a major periodicity at 33.9 nm. Finally, we propose a working model of the interaction of this actin cross-linking protein with actin filaments to form bundles.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/dvg.1020110507
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