Cells of all vertebrates thus far investigated contain a cellular src gene, which appears to be a highly conserved homolog of the Rous sarcoma virus oncogene src. Similar to the Rous sarcoma virus oncogene src, this endogenous cellular src gene codes for a Mr 60,000 phosphoprotein (pp60c~src) which is associated with a kinase activity. This kinase specifically phosphorylates tyrosine residues o...

We transfected Chinese hamster ovary (CHO) cells with a cloned v-mos gene (pHT25). The mos family of oncogenes has previously been shown to have serine-threonine kinase activity. This kinase activity may be required for oncogenic transformation, although its exact biological role is unknown. We found that the transfected cells had an altered morphology, a slower doubling time, and an apparent i...

1. The subcellular distribution of the phosphoprotein fraction of grey matter from guinea-pig brain has been determined. Phosphoproteins occurred in all fractions of the tissue, the mitochondrial fraction containing 29%, supernatant 26%, microsomal fraction 23% and nuclear fraction 15%. The quantity of phosphoproteins per unit quantity of protein was highest in the microsomal fraction and lowes...

A rapid, manyfold increase in phosphorylation of cardiac microsomes consisting primarily of sarcoplasmic reticulum was seen when these membranes were incubated in the presence of a bovine cardiac adenosine 3’:5’-monophosphate (cyclic AMP)-dependent protein kinase (protein kinase) and cyclic AMP. Over 85 % of the 3*P associated with membrane protein under similar conditions was identified cs pho...

Cells of all vertebrates thus far investigated contain a cellular src gene, which appears tobe a highly conserved homolog of the Rous sarcoma virus oncogene src. Similar to the Rous sarcoma virus oncogene src, this endogenaus cellular src gene codes for a M, 60,000 phosphoprotein (pp6oc-src) which is associated with a kinase activity. This kinase specifically phosphorylates tyrosine residues of...

It is now well established that the synthesis of the major protein constituents of milk takes place exclusively in the mammary gland, utilizing as building materials the free amino acids of the blood (1). The research of Aten and Hevesy (2), confirmed subsequently by other workers (3, 4), leaves little room for doubt that the precursor of the casein phosphorus is the inorganic phosphorus of the...

BACKGROUND Human epidermal growth factor receptor (HER) downstream signaling kinases have important effects on tumor response to anti-HER monoclonal antibodies and tyrosine kinase inhibitors. We validated an assay that uses phosphoprotein arrays for measurement of HER downstream signaling functionality in breast carcinomas. METHODS Using the Bio-Plex(R) phosphoprotein array (BPA), we performe...

The rapid appearance of radioactivity in the phosphoprotein fraction of tissues after exposure to inorganic radiophosphate was first noted by Davidson et al. (1). This finding was subsequently confirmed in several laboratories for a variety of cell types (2-5). The physiological function of phosphoproteins is obscure, however, since no direct evidence is yet available for their role in cell met...

Calcium binding properties of bone acidic glycoprotein-75, osteopontin, and bone sialoprotein were determined in 10 mM imidazole buffer (pH 6.8), containing either 60 mM KCl or 150 mM NaCl. Proteins assayed were first bound to nitrocellulose to mimic substrate-bound forms in vivo; retention of phosphoproteins was determined through use of radioiodinated tracers. Binding studies were carried out...

We have previously demonstrated that a wide variety of rodent and human tumor cells secrete markedly elevated levels of a transformation-related phosphoprotein with a molecular weight (depending on animal species) of 58,000 to 69,000. With antibody raised to the tumor-secreted phosphoprotein (rat), we have now identified an antigenically related protein in normal rat and human plasma. The rat p...