Vault mobility depends in part on microtubules and vaults can be recruited to the nuclear envelope.

摘要: Vaults are ribonucleoproteins that may function in intracellular transport processes. We investigated the distribution and dynamics of vaults non-small cell lung cancer cells which labeled with green fluorescent protein. Immunofluorescence experiments showed dispersed throughout cytoplasm; a small fraction is found close proximity to microtubules. Immunoprecipitation corroborated these results showing co-precipitation MVP {beta}-tubulin. Using quantitative fluorescence-recovery after photobleaching (FRAP), we demonstrated vault mobility over longer distances part depends on intact microtubules; moving slower when microtubules depolymerized by nocodazole. Biochemical fractionation indicated associated nucleus, however, no GFP-tagged could be observed inside nucleus. an accumulation at nuclear envelope upon treatment protein synthesis inhibitor cycloheximide. Analysis nucleo-cytoplasmic using substrate containing classical NLS NES expressed {sup +/+} -/-} mouse embryonic fibroblasts differences import/export kinetics, suggesting role for hypothesize subset moves directionally via microtubules, possibly towards