A heterogeneous set of urea-insoluble proteins in dividing PC12 pheochromocytoma cells is passed on to at least the generation of great-granddaughter cells.
About 5% of the total cellular protein synthesized in exponentially dividing PC12 pheochromocytoma cells remains insoluble after extractions with aqueous buffer, nonionic detergent, and a strong denaturant, 6M urea. Single- and double-radiolabel pulse-chase labeling experiments with radioactive leucine indicate that for much of the 6 M urea-insoluble protein there is either a lag between its synthesis and deposition in a urea-insoluble compartment and/or the urea-insoluble protein is comparatively stabilized from destruction. Given the doubling time of PC12 cells, much of the long-lived and urea-insoluble protein of PC12 cells is passed on for at least three generations. Electrophoretic analyses show there are many species of long-lived proteins in the 6M urea-insoluble fraction, displayed as a near continuum of subunit molecular weights.
Weber
D J
DJ
Department of Biochemistry and Biophysics, Oregon State University, Corvallis 97331, USA.
McFadden
P N
PN
D000818:Animals; D002021:Buffers; D002250:Carbon Radioisotopes; D002455:Cell Division / Q000502:physiology; D006207:Half-Life; D007930:Leucine / Q000493:pharmacokinetics; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000378:metabolism; D016716:PC12 Cells / Q000166:cytology* / Q000378:metabolism; D051381:Rats; D012995:Solubility; D014508:Urea / Q000737:chemistry
D002021:Buffers; D002250:Carbon Radioisotopes; D009363:Neoplasm Proteins; D014508:Urea; D007930:Leucine