Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-28992
J Cell Sci 1985 Nov 01;79:199-215.
Show Gene links Show Anatomy links

Xenopus marginal band disassembly by calcium-activated cytoplasmic factors.

Gambino J , Ross MJ , Weatherbee JA , Gavin RH , Eckhardt RA .


Abstract
The marginal band microtubules of isolated Xenopus erythrocyte cytoskeletons possess the stability properties of non-steady-state microtubules. They are unperturbed by low temperatures, a variety of microtubule inhibitors, hypotonic treatment and the direct action of calcium. These microtubules can be rapidly depolymerized by erythrocyte lysis in the presence of calcium or by exposure of cytoskeletons obtained and washed in calcium-free media to calcium-containing supernatants of other cell lysates. Thus, marginal band microtubules are calcium-sensitive only in the presence of cytoplasm. The calcium-activated disassembly of the marginal band does not appear to be the result of general or tubulin-specific proteolysis and is prevented by the calmodulin inhibitor, trifluoperazine. On sodium dodecyl sulphate/polyacrylamide gels, samples of calcium-induced, marginal band disassembled cytoskeletons are always tubulin-depleted and also possess a new high molecular weight polypeptide doublet that is believed to constitute stable partial degradation products of spectrin. In the presence of calcium, addition of calmodulin and ATP to cytoskeletons washed free of cytoplasm does not initiate marginal band disassembly. Therefore, if calmodulin mediates marginal band disassembly, it requires cytoplasmic binding proteins or cytoplasmic cofactors.

PubMed ID: 3914480
Article link: J Cell Sci
Grant support: [+]