Indirect semiquantitative determination of p34cdc2 levels in G1 and G2 cells of the carbohydrate-starved root meristems in Vicia faba var. minor

Abstract

In eukaryotes, the 34kDa kinase (p34) encoded by the <em>cdc2</em> gene is a key regulator of both the onset of DNA synthesis (G<sub>1</sub> to S phase transition) and the onset of mitosis (G<sub>1</sub> to M phase transition). Using mouse anti-human PSTAIRE and FITClabelled goat antibodies, indirect semiquantitative determination of p34<sup><em>cdc2</em></sup> 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 G<sub>1</sub> and G<sub>2</sub> 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 <em>V. faba</em> var. <em>minor</em> 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 p34<sup><em>cdc2</em></sup>.