D cyclins

Edgar Jim Murray in Cambridge has done some interesting work with D cyclins in plants. By overexpressing one of the D cyclins they got tobacco plants that grew quite a bit faster but ended up the same size. The rate of proliferation was altered, but the final size was not. 

Regulated Synthesis of CDKs and Cyclins The third mechanism for changing CDK activity is regulation of the rate of synthesis of cyclin or CDK or both. For example, cyclin D, cyclin E, CDK2, and CDK4 are synthesized only when a specific transcription factor, E2F, is present in... 

Figure 6.18 The PSTAIRE helix undergoes a major conformational change when CDK2 binds to cyclin A. In the inactive free CDK2 (yellow) the active site residue Glu 51 is far from the active site. Upon binding of cyclin A to CDK2 the PSTAIRE helix (hiue) rotates 90° and changes its position so that Glu 51 becomes positioned into the active site. (Adapted from P.D. Jeffry et al.. Nature 376 313-320, 1995.)...

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Dalby, B., and Glover, D. M. (1992). 3 non-translated sequences in Drosophila cyclin B transcripts direct posterior pole accumulation late in oogenesis and perinuclear association in syncitial embryos. Development 115 989-997. 

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Evans, T., Rosenthal, E. T Youngblom, J., Distel, D., and Hunt, T. (1983). Cyclin a protein specified by maternal mRNA in sea urchin eggs that is destroyed at each cleavage division. Cell 33 389-396. 

Galaktionov, K., and Beach, D. (1991). Specific activation of cdc25 tyrosine phosphatases by B-type cyclins evidence for multiple roles of mitotic cyclins. Cell 67 1181-1194. 

Jessus, C., and Beach, D. (1992). Oscillation of MPF is accompanied by periodic association between cdc25 and cdc2-cyclin B. Cell 68 323-332. 

Labbe, J-C., Capony, J-P., Caput, D., Cavadore, J-C., Derancourt, J., Kaghad, M., Lelias, J-M., Picard, A., and Doree, M. (1989a). MPF from starfish oocytes at first meiotic metaphase is a heterodimer containing one molecule of cdc2 and one molecule of cyclin B. EMBO J. 8 3053-3058. 

Raff, J. W Whitfield, W. G. F, and Glover, D. M. (1990). Two distinct mechanisms localise cyclin B transcripts in syncitial Drosophila embryos. Development 110 1249-1261. 

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