Da Costa Marco, Bach Liên, Landrieu Isabelle, Bellec Yannick, Catrice Olivier, Brown Spencer, De Veylder Lieven, Lippens Guy, Inzé Dirk, Faure Jean-Denis
Laboratoire de Biologie Cellulaire, Institut National de la Recherche Agronomique, F-78026 Versailles Cedex, France.
Plant Cell. 2006 Jun;18(6):1426-37. doi: 10.1105/tpc.105.040485. Epub 2006 May 12.
PASTICCINO2 (PAS2), a member of the protein Tyr phosphatase-like family, is conserved among all eukaryotes and is characterized by a mutated catalytic site. The cellular functions of the Tyr phosphatase-like proteins are still unknown, even if they are essential in yeast and mammals. Here, we demonstrate that PAS2 interacts with a cyclin-dependent kinase (CDK) that is phosphorylated on Tyr and not with its unphosphorylated isoform. Phosphorylation of the conserved regulatory Tyr-15 is involved in the binding of CDK to PAS2. Loss of the PAS2 function dephosphorylated Arabidopsis thaliana CDKA;1 and upregulated its kinase activity. In accordance with its role as a negative regulator of the cell cycle, overexpression of PAS2 slowed down cell division in suspension cell cultures at the G2-to-M transition and early mitosis and inhibited Arabidopsis seedling growth. The latter was accompanied by altered leaf development and accelerated cotyledon senescence. PAS2 was localized in the cytoplasm of dividing cells but moved into the nucleus upon cell differentiation, suggesting that the balance between cell division and differentiation is regulated through the interaction between CDKA;1 and the antiphosphatase PAS2.
PASTICCINO2（PAS2）是类蛋白酪氨酸磷酸酶家族的成员之一，在所有真核生物中保守，其特征是催化位点发生突变。尽管类酪氨酸磷酸酶蛋白在酵母和哺乳动物中至关重要，但其细胞功能仍不清楚。在此，我们证明PAS2与酪氨酸磷酸化的细胞周期蛋白依赖性激酶（CDK）相互作用，而不与其未磷酸化的异构体相互作用。保守的调节性酪氨酸15的磷酸化参与CDK与PAS2的结合。PAS2功能丧失使拟南芥CDKA;1去磷酸化并上调其激酶活性。与其作为细胞周期负调节因子的作用一致，PAS2的过表达在悬浮细胞培养物的G2到M期转换和早期有丝分裂阶段减缓了细胞分裂，并抑制了拟南芥幼苗的生长。后者伴随着叶片发育改变和子叶衰老加速。PAS2定位于分裂细胞的细胞质中，但在细胞分化时移入细胞核，这表明细胞分裂与分化之间的平衡是通过CDKA;1与抗磷酸酶PAS2之间的相互作用来调节的。
