Acetylated and detyrosinated α‐tubulins are co‐localized in stable microtubules in rat meningeal fibroblasts

Abstract

We have examined the distribution of acetylated α‐tubulin using immunofluorescence microscopy in fibroblastic cells of rat brain meaninges. Meningeal fibroblasts showed heterogenous staining patterns with a monoclonal antibody against acetylated α‐tubulin ranging from staining of primary cilia or microtubule‐organising centers (MTOCs) alone to extensive microtubule networks. Staining with a broad spectrum anti‐α‐tubulin monoclonal indicated that all cells possessed cytoplasmic microtubule networks. From double‐labeling experiments using an antibody against acetylated α‐tubulin (6–11B‐1) and antibodies against either tyrosinated or detyrosinated α‐tubulin, it was found that acetylated α‐tubulin and tyrosinated α‐tubulin were often segregated to different microtubules. The microtubules containing acetylated but not tyrosinated α‐tubulin were cold stable. Therefore, it appeared that in general meningeal cells possessed two subset of microtubules: One subset contained detyrosinated and acetylated α‐tubulin and was cold stable, and the other contained tyrosinated α‐tubulin and was cold labile. These results are consistent with the idea that acetylation and detyrosination of α‐tubulin are involved in the specification of stable microtubules.