![]() However, while repressing WEE1 expression was shown to alter the development of tomato 5, in Arabidopsis thaliana, wee1 mutants were not morphologically different from the wild-type 10. Indeed, the phosphorylation of tyrosine residue(s) of CDKA 1 by plant WEE1s leads to a decrease in CDKA 1 activity 3, 5, 9, 10, similarly to human CDK1 and the fission yeast ortholog CDC2 1, 2. Later, plant WEE1-like proteins were repeatedly described as protein kinases that negatively impact plant cell division and growth, suggesting a conserved phosphorylation cascade between eukaryotes for cell cycle regulation 3, 4, 5, 6, 7, 8. The function of WEE1 was first described for yeast and then human as an inhibitory Tyr-phosphorylation of CDKs, leading to cell cycle arrest 1, 2. The structural differences, which could be responsible for the loss of specificity between human and plants, are highlighted and suggest the involvement of plant WEE1 in more cell regulation processes. However, some substitutions of an arginine and a glutamate at the entrance of the catalytic pocket, illustrated by 3D structure predictions, challenged the specificity of this protein toward the substrate and Tyr-phosphorylation compared to the human WEE1. A detailed sequence analysis confirmed the catalytic potential of WEE1 proteins in plants. We analyzed the phylogenetic distribution of amino-acid sequences among a large number of plants by Bayesian analysis that highlighted the general conservation of WEE1 proteins. In this in silico study, we assessed the structural conservation of the WEE1 protein in the plant kingdom with a particular focus on agronomically valuable plants, the legume crops. However, analogies with the control of the human cell cycle by tyrosine- (Tyr-) phosphorylation of cyclin-dependent kinases (CDKs) are sometimes questioned. The WEE1 kinase is ubiquitous in plant development and negatively regulates the cell cycle through phosphorylations. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |