Microtubules containing detyrosinated tubulin are less dynamic.
Peptide antibodies specific for tyrosinated (tyr-tubulin) or detyrosinated alpha-tubulin (glu-tubulin) have been generated for studying the relative stability of microtubules enriched in either form of alpha-tubulin. Treatment of Vero cells with nocodazole has revealed that interphase microtubules rich in glu-tubulin (glu-microtubules) are resistant to higher concentrations of the microtubule-disrupting drug than the microtubules containing only tyr-tubulin (tyr-microtubules). Glu-tubulin is enriched in centrioles and mid-bodies, but absent from the first interphase microtubules that have repolymerized in late telophase. Tubulin (including both forms) has been labeled with rhodamine (rh-tubulin) and microinjected into Vero cells to study in vivo the dynamic properties and incorporation rates of tubulin into microtubules rich in either glu- or tyr-tubulin. Tyr-microtubules are significantly more rapidly labeled by the microinjected rh-tubulin than glu-microtubules. Ten minutes after injection, rh-tubulin is present in virtually all tyr-microtubules. The half-time of turnover of glu-microtubules is approximately 1 h. Even several hours after microinjection, some of the glu-microtubules have consistently not incorporated visible amounts of rh-tubulin. These results suggest that tyr- and glu-microtubules respectively represent relatively dynamic and stable subclasses of interphase microtubules.
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European Molecular Biology Laboratory, Heidelberg, FRG.
D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology; D001921:Brain / Q000378:metabolism; D002417:Cattle; D005455:Fluorescent Antibody Technique; D007700:Kinetics; D046911:Macromolecular Substances; D008870:Microtubules / Q000187:drug effects / Q000648:ultrastructure*; D015739:Nocodazole; D014404:Tubulin / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism; D014709:Vero Cells
D001562:Benzimidazoles; D046911:Macromolecular Substances; D014404:Tubulin; D014443:Tyrosine; D015739:Nocodazole