Cloning And Function Analysis Of Oryza Sativa Extracellular Calcium-sensing Receptor (CAS) Gene

Calcium(Ca2+) is a critical second messenger connecting extra- and intracellular reaction in signal transduction. Extracellular Ca2+ is required for various physiological and developmental processes in animals and plants. Calcium-sensing receptor is a Ca2+ permeableable channel of cytoplasm membrane,which is essential to maintain relatively constant internal Ca2+ content. In plants,calcium-sensing receptor (CAS) cansenses the level of extra- cellular Ca and lead closure of stomatal. More research on this gene of crop or lawn will help to fight drought and make a foundation for thrift of water. At the same time ,the research of CAS will help to make sure the mechnism of Ca2+ signal transduction and lead a new way to fight for stress. In this study, the gene of CAS has been cloned and registered in GenBank, which will be futher applied to study gene function in Oryza sativa.In this study, CAS gene of Oryza sativa was cloned by RT-PCR .Some work has been done to the sequence and function of this gene. Homologue sequences of CAS gene and protein exist between Oryza sativa and arabidopsis. Database searches identified several homologues in other plant species. In Oryza sativa CAS has one transmembrane domain which is made of a-helix. The carboxy terminus is possibly intracellular, and has sequence similarity to a hodanese domain, which is likely to have a role in protein-protein interactions. This domain is also found in phosphatases and a variety of proteins such as sulfide ehydrogenases and certain stress proteins such as senesence specific protein, PspE and GlpE in bacteria and cyanide and arsenate resistance proteins,which sugests it play a important role in fight stresse. In our lab the expression of this gene is analysised by Northern blotting in Ca2+ menace. In order to make a deep research on this gene functions on keeping Ca2+ homeostasis,mechnism of signal transduction and fight stress, we have constructed anti-sense vector of PBI-CAS. Antisense RNA technique is a efficient way to study gene function. The vector of pcDNA3-CAS which has been constructed will be tested in cells of HEK293.Further working is going on.Rice is one of the most important crops in world,and the sequence of its genome has been published.The reseach on CAS of Oryza sativa is more important and practicable in future.