Several complementary techniques, including immunocytochemical and immunobiochemical analyses, two-dimensional gel electrophoresis, and peptide mapping, were used in this study to examine the involvement of caldesmon in lymphocyte receptor capping. We have found a lymphoma 140-kDa polypeptide that is structurally similar to muscle caldesmon, suggesting that this polypeptide may be a lymphoma caldesmon. When lymphoma 140-kDa polypeptide is extracted from permeabilized cells using 25 mM MgCl2, capping is inhibited. Adding the 140-kDa protein or gizzard caldesmon back to the extracted cells restores their ability to cap. These findings suggest that actin-linked regulatory proteins such as caldesmon may be critically important to actomyosin-mediated contraction which, in turn, is responsible for collecting receptors into cap structures.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Biological Chemistry|
|State||Published - Jan 1 1989|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology