Identification of cyst wall proteins of the hypotrich ciliate Euplotes encysticus using a proteomics approach

Euplotes encysticus is a species of Hypotrich ciliates, which form cyst wall by secreting the special substances on encounter of adverse environment. It has critical significance to study the component and mechanism underlying resting cyst, during resisting unfavorable conditions in dormancy induction. The present study was aimed to investigate the effects of cyst wall proteins of Euplotes encysticus by using biochemical methods. Therefore, protein extracts were separated by SDSPAGE, identified and analyzed by MALDI-TOF MS and Bioinformatics tools. We detected 42 cyst wall proteins, 26 were functional proteins and 16 proteins consist of unknown function; which is consistent with cyst wall specificity. These results partially revealed the components of resting cyst wall formed after the cells differentiation of Euplotes encysticus. In addition, our data suggested that the function of cyst wall proteins are more likely involved in the mechanical protection, signal transduction, material transport, protein degradation and energy metabolism to survival, with potentially importance implications in the molecular mechanism of eukaryocyte dormancy under stress condition.