Plasma membrane localization of palmitoylated tubulin.
PC12 pheochromocytoma cells incorporate [(3)H]palmitic acid into tubulin in a time- and cell-density-dependent manner. The plasma membrane-enriched fraction contains most of the radioactivity of the membrane pellet. While palmitoylated tubulin is found in both the cytoplasm and particulate fraction, the bulk of [(3)H]palmitic acid bound to tubulin is present in the crude membrane pellet and the tubulin extracted from the plasma membrane is more heavily palmitoylated than that extracted from endoplasmic reticulum. Detergent-extracted tubulin from plasma membrane is, to a large extent, polymerization competent; a substantial fraction, increasing as a function of labeling time, is not hydroxylamine-labile. The requirement for detergent extraction, the accompanying changes in tubulin properties and the present findings of preferential incorporation of labeled tubulin into plasma membranes, make it clear that direct incorporation of tubulin into the plasma membrane can occur.
Zambito
A M
AM
Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, 20892, USA. annaz@intra.niddk.nih.gov
Wolff
J
J
D000818:Animals; D002452:Cell Count; D002458:Cell Fractionation; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism*; D003593:Cytoplasm / Q000737:chemistry; D004721:Endoplasmic Reticulum / Q000737:chemistry; D006878:Hydroxides / Q000737:chemistry; D019811:Hydroxylamine / Q000737:chemistry; D016716:PC12 Cells / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D019308:Palmitic Acid / Q000378:metabolism* / Q000493:pharmacokinetics; D017680:Potassium Compounds / Q000737:chemistry; D011233:Precipitin Tests; D051381:Rats; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014316:Tritium; D014404:Tubulin / Q000737:chemistry* / Q000378:metabolism*
D006878:Hydroxides; D017680:Potassium Compounds; D013438:Sulfhydryl Compounds; D014404:Tubulin; D014316:Tritium; D019811:Hydroxylamine; D019308:Palmitic Acid; C029943:potassium hydroxide