Abstract
In eukaryotes, the 34kDa kinase (p34) encoded by the cdc2 gene is a key regulator of both the onset of DNA synthesis (G1 to S phase transition) and the onset of mitosis (G1 to M phase transition). Using mouse anti-human PSTAIRE and FITClabelled goat antibodies, indirect semiquantitative determination of p34cdc2 levels was performed in meristematic cells from the control (intact) and excised, carbohydrate-starved main roots of Vicia faba var. minor. No evident differences in the intensity of fluorescence was found either between the G1 and G2 cells or between the control cells and the cells arrested at both Principal Control Points by carbohydrate starvation. It seems thus, that the cell cycle block induced in meristematic cells of V. faba var. minor is not correlated with the absolute level of the key cell cycle enzyme responsible for phosphory-lution of cellular proteins, but primarily with the altered activity of p34cdc2.
Keywords
cell cycle; p34cdc2; Principal Control Point hypothesis; protein kinases; root meristems; Vicia faba var. minor