The 70-kDa neurofilament protein subunit (NF-L) is phosphorylated in vivo on at least three sites (L1 to L3) (Sihag, R. K. and Nixon, R. A. (1989) J. Biol. Chem. 264, 457-464). The turnover of phosphate groups on NF-L during axonal transport was determined after the neurofilaments in retinal ganglion cells were phosphorylated in vivo by injecting mice intravitreally with [32P]orthophosphate. Tw...

Herbicide resistance in Chlamydomonas reinhardii cells was induced by mutagenesis with 5-fluorodeoxyuridine and ethylmethanesulfonate. Four mutant strains were isolated and analyzed for resistance against DCM U-type or phenolic inhibitors o f photosynthetic electron transport. The mutants were different in both the extent and the pattern o f their resistance: the R /S value, i.e. the ratio o f ...

High-affinity insulin receptors exist in the organ of Corti (Kd = 1.1 +/- 0.5 nM) and in the lateral wall (stria vascularis and ligamentum spirale; Kd = 1.1 +/- 0.4 nM) of the inner ear of the guinea pig as determined by the binding of radiolabeled porcine or bovine insulin in vitro. Carrier-mediated transport of glucose (defined as the cytochalasin B-sensitive part of total uptake) was measure...

Previous studies on the topography of the reactions leading to the formation of dolichol-P-P-Glc-NAc2Man9Glc3 have shown that these occur on both sides of the endoplasmic reticulum membrane (Hirschberg, C. B., and Snider, M. D. (1987) Annu. Rev. Biochem. 56, 63-87). Dolichol-P-P-GlcNAc2Man5 has been detected on the cytoplasmic side of the endoplasmic reticulum membrane while the subsequent doli...

A 32P-labeled pyruvate kinase (L-type isozyme) was elicited in response to glucagon and has been isolated from suspensions of hepatocytes incubated with inorganic [32P]phosphate. The pyruvate kinase in crude extracts of hepatocytes was stabilized by ammonium sulfate fractionation, 30% glycerol, and 50 mM KF and the enzyme was isolated by immunoprecipitation with anti-liver pyruvate kinase immun...

The human erythrocyte actively phosphorylates and dephosphorylates phosphatidylinositol present in the membrane in an apparent "futile cycle." Recent reports have proposed that this phosphorylation/dephosphorylation cycle is a significant consumer of adenosine-5'-triphosphate (ATP) in the erythrocyte. This study details two independent techniques for quantitating the ATP consumed by this phosph...

Mitogenic stimulation of quiescent mouse 3T3 cells with epidermal growth factor leads to biphasic S6 kinase activation. The kinases present in both phases of the response have been purified from 32P-labeled cells and shown to contain a phosphoprotein of equivalent Mr 70,000. Chromatographic analysis of the purified S6 kinases on a Mono Q column reveals that (i) all 32P-labeled protein coelutes ...

Incorporation of 32p into RNA and DNA fractions of mammary and tumor tissue was studied in virgin C3H mice, which are susceptible to the development of breast cancer. Virgin C57BL mice, which are resistant to the development of breast cancer, were the controls. Virgin C3H and C57BL mice, 4 and a months old, and tumor-bearing C3H mice were used as the experimental groups. The incorporation of 32...

In 1954 a then 31 -yr-old male was found to have erythrocytosis. Over the ensuing decade he received 72 mCi 32P. In 1964 his daughters were found to have erythrocytosis. Further investigation led to the discovery of hemoglobin Yakima, a variant with high oxygen affinity. He received no further therapy and was well until 1975, when he developed the preleu. kemic syndrome. Within 12 mo he develop...

The regulatory molecule, cyclic adenosine 3':5'-monophosphate (cAMP), can inhibit cell proliferation, reverse the neoplastic phenotype, and promote tumor regression. Since the biological effects of cAMP are mediated by an activation of protein kinase enzymes, the interaction of cAMP with the regulatory subunits of type I and II isozymes (Ri and RN)was studied in normal and neoplastic tissues. R...