Phospholipase activity is elevated in dividing cells. In response to growth factor stimulation, phospholipase C-gamma (PLC-gamma) binds to activated tyrosine kinase receptors via SH2 binding domains, resulting in phosphorylation of PLC-gamma and activation of its enzyme activity. These observations suggest that PLC-gamma participates in the signal transduction pathway employed by growth factors to promote mitogenesis.
View Article and Find Full Text PDFE2F is a mammalian transcription factor involved in cell cycle regulation. The retinoblastoma gene product, pRB, binds to E2F in a cell cycle-dependent manner and appears to turn E2F from a transcriptional activator into a repressor. We show here that in vitro binding of pRB has three major effects on the DNA binding properties of E2F affinity-purified from HeLa cells; pRB binding increases the half-life of E2F.
View Article and Find Full Text PDFE2F is a mammalian transcription factor that appears to play an important role in cell cycle regulation. While at least two proteins (E2F-1 and DP-1) with E2F-like activity have been cloned, studies from several laboratories suggest that additional homologs may exist. A novel protein with E2F-like properties, designated E2F-2, was cloned by screening a HeLa cDNA library with a DNA probe derived from the DNA binding domain of E2F-1 (K.
View Article and Find Full Text PDFTo assess the effect of oral candidiasis (OC) associated with human immunodeficiency virus (HIV) at initial hospital admission on both survival and hospital use, a retrospective analysis was performed in 1,172 hospitalized patients identified by an HIV surveillance program at an inner city public hospital in East Harlem, New York. Survival times were compared using three different HIV staging schemes placing patients with OC into either a common stage with adenopathy patients (Scheme IHS-URV), a common stage with acquired immune deficiency syndrome patients (AIDS; Scheme WRCDC), or an intermediate stage between AIDS patients and all others (Scheme ORAL). Patients without AIDS demonstrated a significantly increased risk of dying (relative risk, 2.
View Article and Find Full Text PDFE2F is a mammalian transcription factor that appears to play an important role in cell cycle control. DNA affinity column-purified E2F from HeLa cells reproducibly exhibits multiple protein bands when analyzed by SDS/PAGE. After electrophoretic purification, electroelution, and refolding of the individual protein components, the E2F DNA binding activity of the individual proteins was poor.
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