Polyproline-rich Peptides Organize 4 Cholinesterase Subunits into A Tetramer; BChE and AChE Scavenge Polyproline Peptides Released during Metabolic Turnover

The EJ bladder carcinoma oncogene is activated by a point mutation in the c-rasH proto-oncogene at the 12th amino acid codon. In an attempt to understand the mechanism of oncogenic activation, a comparative study was undertaken to examine the metabolic turnover and subcellular localization of the p21 protein encoded by the EJ oncogene, the viral oncogene, and its normal cellular homolog. Pulse-labeling experiments indicated that both c-ras p21 proteins were synthesized by a very similar pathway, as was observed for the viral p21 protein of Harvey murine sarcoma virus. The pro-p21 proteins were detected in free cytosol, and the processed products were associated with plasma membrane. The intracellular half-life of p21 proteins was determined by pulse-labeling and chasing in the presence of excess unlabeled methionine. Although both p21 proteins of EJ and the normal c-ras genes which are not phosphorylated have a half-life of 20 h, the viral p21 protein of Harvey murine sarcoma virus which includes a phosphorylated form is much more stable in cells, having a half-life of 42 h, apparently due to phosphorylation.

Download Full-text

Fractionation and metabolic turnover of carbon and nitrogen stable isotopes in black fly larvae

Rapid Communications in Mass Spectrometry ◽

10.1002/rcm.3413 ◽

2008 ◽

Vol 22 (5) ◽

pp. 694-700 ◽

Cited By ~ 28

Author(s):

Jay P. Overmyer ◽

M. Aaron MacNeil ◽

Aaron T. Fisk

Keyword(s):

Stable Isotopes ◽

Nitrogen Stable Isotopes ◽

Black Fly ◽

Carbon And Nitrogen ◽

Metabolic Turnover ◽

Fly Larvae

Download Full-text

Metabolic turnover of phosphorylation sites in simian virus 40 large T antigen.

Journal of Virology ◽

10.1128/jvi.45.1.442-446.1983 ◽

1983 ◽

Vol 45 (1) ◽

pp. 442-446 ◽

Cited By ~ 4

Author(s):

F Van Roy ◽

L Fransen ◽

W Fiers

Keyword(s):

Simian Virus 40 ◽

Simian Virus ◽

T Antigen ◽

Phosphorylation Sites ◽

Large T Antigen ◽

Metabolic Turnover

Download Full-text

Stimulation of Na(+)-K(+)-ATPase by thyrotropin in cultured thyroid follicular cells

AJP Cell Physiology ◽

10.1152/ajpcell.1995.268.5.c1252 ◽

1995 ◽

Vol 268 (5) ◽

pp. C1252-C1258 ◽

Cited By ~ 8

Author(s):

T. A. Pressley ◽

S. C. Higham ◽

L. A. Joson ◽

D. W. Mercer

Keyword(s):

Thyroid Stimulating Hormone ◽

Follicular Cells ◽

Hormone Synthesis ◽

Metabolic Turnover ◽

Striking Increase ◽

Thyroid Follicular Cells ◽

A Cell ◽

Messenger System ◽

Rat Thyroid ◽

Stimulation Of

Thyroid-stimulating hormone (TSH; thyrotropin) produces a pleiotropic response in the thyroid gland, accelerating nearly every aspect of metabolic turnover within the follicular epithelia. We examined the effects of TSH on expression of Na(+)-K(+)-ATPase in FRTL-5 cells, a cell line derived from rat thyroid. TSH (10 mU/ml) produced a nearly twofold increase in abundance of the mRNA encoding the catalytic alpha 1-subunit within 6 h of treatment. With the four mRNAs encoding the beta 1-subunit, TSH produced a striking increase in abundance, but this regulation was discoordinate, and some species increased more than others. Similar increases in mRNA abundance were elicited by activators of the adenosine 3',5'-cyclic monophosphate second messenger system. In contrast to the alpha 1- and beta 1-mRNAs, the abundance of the mRNA encoding the beta 2-subunit was unchanged with TSH after 6 h, indicating that the effects of thyrotropin were not universal or indiscriminate. Thyrotropin also caused a 76% increase in Na(+)-K(+)-ATPase activity and a 46% increase in pump-mediated transport after 48 h. These studies suggest that the changes in metabolic turnover initiated by TSH during hormone synthesis include upregulation of the N(+)-K+ pump.

Download Full-text