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-20006
J Cell Biol 1995 Mar 01;1285:879-91.
Show Gene links Show Anatomy links

Protein phosphatase 1 regulates the cytoplasmic dynein-driven formation of endoplasmic reticulum networks in vitro.

Allan V .


???displayArticle.abstract???
Interphase Xenopus egg extracts form extensive tubular membrane networks in vitro. These networks are identified here as endoplasmic reticulum by the presence of ER resident proteins, as shown by immunofluorescence, and by the presence of single ribosomes and polysomes, as shown by electron microscopy. The effect of phosphorylation on ER movement in interphase was tested using the phosphatase inhibitor, okadaic acid. Okadaic acid treatment resulted in an increase of up to 27-fold in the number of ER tubules moving and in the extent of ER networks formed compared to control extracts. This activation was blocked by the broad-specificity kinase inhibitor 6-dimethylaminopurine. Okadaic acid had no effect, however, on the direction of ER tubule movement, which occurred towards the minus end of microtubules, and was sensitive to low concentrations of vanadate. Inhibition of phosphatases also had no effect on the speed or duration of ER tubule extensions, and did not stimulate the activity of soluble cytoplasmic dynein. The sensitivity of ER movement to okadaic acid closely matched that of protein phosphatase 1. Although the amount of ER motility was greatly increased by inhibiting protein phosphatase 1 (PP1), the amount of cytoplasmic dynein associated with the membrane was not altered. The data support a model in which phosphorylation regulates ER movement by controlling the activity of cytoplasmic dynein bound to the ER membrane.

???displayArticle.pubmedLink??? 7876311
???displayArticle.pmcLink??? PMC2120396



Species referenced: Xenopus
Genes referenced: dnai1 dync1li1 npy4r

References [+] :
Alexandrova, Motility of intracellular particles in rat fibroblasts is greatly enhanced by phorbol ester and by over-expression of normal p21N-ras. 1993, Pubmed