Abstract：Cajal body (CB) is a significant component of nucleus, playing roles in growth and deveplopment of animal and plants, and the progress of virus infection, coilin is the protein marker of CB. In order to understand the function and subcellular localization of Arabidopsis thaliana coilin (Atcoilin), the cDNA sequence of Atcoilin was amplified by RT-PCR from Arabidopsis thaliana, then cloned and identified by sequencing. The subcellular localization and functional domains of Atcoilin were predicted using bioinformatics softwares. Atcoilin was ligated into expression vector pEarley101 bearing yellow fluorescent protein (YFP). Recombinant protein Atcolin-YFP were transiently expressed on the leaf epidermis cells of Nicotiana benthamiana by using Agrobacterium-infiltration, the subcellular localization of protein was observed under the confocal laser scanning microscope (CLSM). The bioinformatics analysis showed that Atcoilin localized to the nuclear, encoded 608 amino acids and contained three functional domains (N-terminal ordered domain, central internal disordered domain and C-terminal domain). Atcoilin had higher homologous in amino acid with human coilin, and its homology was 50%. The expression of Atcoilin-YFP was also verified by Western bolting analysis, under the CLSM, Atcoilin-YFP localized in the nuclear. Function prediction and subcelluar localization analysis can provide the foundation for the further research on coilin.
