+ Resolve Article
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter

+ Translate
+ Subscribe to Site Feed
GeoScience Most Shared ContentMost Shared Content

E1A induces phosphorylation of the retinoblastoma protein independently of direct physical association between the E1A and retinoblastoma products

, : E1A induces phosphorylation of the retinoblastoma protein independently of direct physical association between the E1A and retinoblastoma products. Molecular and Cellular Biology 11(8): 4253-4265

We have studied the initial effects of adenovirus E1A expression on the retinoblastoma (RB) gene product in normal quiescent cells. Although binding of the E1A products to pRB could, in theory, make pRB phosphorylation unnecessary for cell cycle progression, we have found that the 12S wild-type E1A product is capable of inducing phosphorylation of pRB in normal quiescent cells. The induction of pRB phosphorylation correlates with E1A-mediated induction of p34cdc2 expression and kinase activity, consistent with the possibility that p34cdc2 is a pRB kinase. Expression of simian virus 40 T antigen induces similar effects. Induction of pRB phosphorylation is independent of the pRB binding activity of the E1A products; E1A domain 2 mutants do not bind detectable levels of pRB but remain competent to induce pRB phosphorylation and to activate cdc2 protein kinase expression and activity. Although the kinetics of induction are slower, domain 2 mutants induce wild-type levels of pRB phosphorylation and host cell DNA synthesis and yet fail to induce cell proliferation. These results imply that direct physical interaction between the RB and E1A products does not play a required role in the early stages of E1A-mediated cell cycle induction and that pRB phosphorylation is not, of itself, sufficient to allow quiescent cells to divide. These results suggest that the E1A products do not need to bind pRB in order to stimulate resting cells to enter the cell cycle. Indeed, a more important role of the RB binding activity of the E1A products may be to prevent dividing cells from returning to G0.


PMID: 1830128

DOI: 10.1128/mcb.11.8.4253

Other references

Dawson, C.O.; Wiseman, A.; Pirie, H.M.; Breeze, R.G., 1977: Studies on the incidence and titres of precipitating antibody to Micropolyspora faeni in sera from adult cattle. Over 2 consecutive years, serum samples, taken in autumn and spring from all housed adult cattle in 16 herds, were examined for the presence and amount of precipitating antibody to Micropolyspora faeni. Exposure to the allergen over the winter mon...

Fires M., 1980: Recording heart rate by a small computer. Pracovni Lekarstvi 32(10): 346-348

Jurkiewicz W., 1976: Organization of data storage and retrieval in the Polish Geological Institute. Przeglad Geologiczny 12): 723-726

Lwebuga-Mukasa, J.S.; Oyana, T.J.; Wydro, P., 2004: Risk factors for asthma prevalence and chronic respiratory illnesses among residents of different neighbourhoods in Buffalo, New York. Study objective: The aim of this study is to identify risk factors for asthma prevalence and chronic respiratory illnesses in Buffalo's neighbourhoods after previous studies reported increased levels of asthma among residents on Buffalo'...

Beskokotov, YuA., 1992: Aesculapiuss son. Priroda (Moscow). Sentyabr'; 9925: 54-55

Seethapathi, N.; Srinivasan, M., 2016: The metabolic cost of changing walking speeds is significant, implies lower optimal speeds for shorter distances, and increases daily energy estimates. Humans do not generally walk at constant speed, except perhaps on a treadmill. Normal walking involves starting, stopping and changing speeds, in addition to roughly steady locomotion. Here, we measure the metabolic energy cost of walking when cha...

Iyer, R.Shankar.; Thomas, B.; Akhtar, S.; Kumar, P., 2017: Olfactory nerve hypertrophy: a clue to the presence of ipsilateral megalencephaly. Bmj Case Reports 2017

Rosenfeld, J.M.; Daley, J.D.; Ohno, S.; YoungLai, E.V., 1977: Central aromatization of testosterone in testicular feminized mice. Aromatization of testosterone was examined in hypothalamic and cerebral cortex tissues from 32 mice--10 normal males, 10 normal females, 2 carrying the testicular feminized gene (Tfm) and 10 Tfm with the modifying (Ohv) gene. Total aromatization w...

Valentino, M.; Ruschioni, A.; Rocco, M.; Comai, M.; Governa, M., 1986: Chemotaxic activity of granulocytes in toluene diisocyanate-induced asthma. Bollettino Della Societa Italiana di Biologia Sperimentale 62(10): 1245-1252

Dukes, Tw, 1976: Phototoxicity in animals. Progress Biometeorion B: 91-95.