Petunia p34cdc2 protein kinase activity in G2/M cells obtained with a reversible cell cycle inhibitor, mimosine

FEBS Letters

Qin, Li-Xian¹  Perennes, Claudette¹  Glab, Nathalie²  Bergounioux, Catherine¹ 

[1] Laboratoire de Physiologie Végétale Moléculaire CNRS, URA 1128, Faculté des Sciences, 91405 Orsay, France;Centre de Génétique Moléculaire, CNRS, UPR 2420, 91198 Gif sur Yvette, France

关键词: Cell cycle;    p34cdc2;    Protoplast;    Mimosine;    Petunia;   

DOI  :  10.1016/0014-5793(93)80392-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Protoplasts isolated from petunia leaf mesophyll are non-cycling cells mostly with 2C content. Cells regenerating from protoplast culture enter mitosis after 48 h. This experimental model is used to relate p34^cd2 kinase activity to cell cycle phase. Our results show that the histone Hl phosphorylation, and hence p34^cdc2 kinase activity, peaks with G₂+ early M cell cycle phase. However, a trace kinase activity was already present when most cells were entering S phase. To obtain a maximum of cells in G₁+S phases, the protoplast culture was treated with the rare amino acid, mimosine. Mimosine blocked plant cells derived from protoplast culture both at g₁ and in early and mid S phase. Despite the increased G₁+S level, p34^cdc2 kinase activity did not increase. This suggests that the trace activity appearing when the majority of cells are entering S does not correspond to any putative P34^cdc2 activation at G₁/S transition but to the activation of the minor 4C population initially present in the leaf: the hypothesis remains that p34^cdc2 kinase activity is solely related to G₂+M phase in petunia.

【 授权许可】

Unknown