Evidence for the presence of non-receptor protein tyrosine kinases in algal cells

Abstract

Two orders of green alga (Cladophorales and Charales) were investigated for the presence of protein tyrosine kinase activity. Proteins of 70 and 85 kDa were found to be tyrosine phosphorylated in Cladophora fracta, with an additional phosphorylated band evident at the 120-kDa region in Chara vulgaris, suggestive of the presence of putative tyrosine kinase activity in these algal species. A 70-kDa protein was immunoprecipitated from both species using a polyclonal antibody against non-receptor protein tyrosine kinase Syk. The protein was found to be phosphorylated on tyrosine, which was prevented upon pretreatment of algal cells with piceatannol. The extent of phosphorylation directly correlated with algal growth, suggesting a link between Syk kinase activity and growth signaling. These observations supported the presence of Syk-like kinase in the green algal species, which could have critical role in the algal growth and development.

Inhibitors of tyrosine kinases and phosphatases as a tool for the investigation of microtubule role in plant cold response

“…Bioinformatics approaches allowed us to demonstrate the similarity of some Arabidopsis proteins with the unknown functions to the profiles of animal tyrosine specific protein kinases [48]. Moreover, in green alga the tyrosine kinases (Syk-like) with the putative key role in growth and development were identified [49].…”

Effects of tyrosine kinase and phosphatase inhibitors on mitosis progression in synchronized tobacco BY-2 cells

“…Using bioinformatics methods on the basis of homology to the Mus musculus Zap70 tyrosine kinase catalytic domain, the existence of 494 protein kinase genes in A. thaliana was predicted. Moreover non-receptor Syk-like tyrosine kinase was identified in the green algal species, which could have a critical role in algal growth and development [7].…”