Crosslinking of actin filaments is caused by caldesmon aggregates, but not by its dimers.
A recent report by Bretscher [(1984) J. Biol. Chem. 259, 12873-12880] showed that caldesmon prepared by his method crosslinks actin filaments to form thick bundles. This is in contrast to the results of previous work that caldesmon binds to F-actin but does not cause any gelation [(1981) Proc. Natl. Acad. Sci. USA 78, 5652-5655]. The present work clearly showed that caldesmon purified according to Bretscher does not cause any gelation of F-actin. However, caldesmon aggregates formed by concentration or by freeze-thawing gelated F-actin to form bundles.
Sobue
K
K
Takahashi
K
K
Tanaka
T
T
Kanda
K
K
Ashino
N
N
Kakiuchi
S
S
Maruyama
K
K
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002148:Calmodulin-Binding Proteins; D002645:Chickens; D002850:Chromatography, Gel; D005895:Gizzard, Avian / Q000032:analysis; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*
D000199:Actins; D002148:Calmodulin-Binding Proteins; D046911:Macromolecular Substances; D010749:Phosphoprotein Phosphatases