Microtubules isolated from the nematode Caenorhabditis elegans contain long stretches of periodic cross-links formed by microtubule-associated proteins (MAPs). These cross-links are 5.7 nm long, 3 nm wide, and occur at one tubulin dimer (8-nm) intervals along the walls of microtubules (Aamodt, E., and J. Culotti, 1986. J. Cell Biol. 103:23-31). The structural protein of the cross-links was isolated from the MAPs by centrifugation and exclusion chromatography. The cross-links were formed exclusively from the most prevalent MAP, a 32,000 mol wt protein. We suggest the name adligin for this MAP. Adligin eluted from the exclusion column at 33,000 mol wt indicating that it was a monomer in solution. Antibodies were made against the purified adligin and affinity purified. The affinity-purified antibodies were used to locate adligin in situ and to determine its distribution relative to that of tubulin by the use of double label immunofluorescence. The anti-adligin antibodies labeled a fibrous network in the cytoplasm of most cells of C. elegans. Neurons were labeled especially well. This labeling pattern was similar to the labeling pattern obtained with antitubulin, but anti-adligin labeled some granules in the gut that were not labeled with antitubulin. These results suggest that adligin may be part of the interphase microtubule network in C. elegans.
ASJC Scopus subject areas
- Cell Biology