Cloning And Identification Of Cotton GhSH1a Gene

Cotton is an important commercial crop as a main source of natural fiber. Studies on the functions of cotton gene are to provide theoretic foundition for cotton genetic modification. A SINA homologous clone was screened from cotton (Gossypium hirsutum L.) cDNA library in this study and was termed GhSHla. Sequencing analysis showed that GhSH1a cDNA was 1394 bp in length, encoding a 339-AA peptide. Cotton GhSHla protein shares about 30% amino acid identity with Drosophila SINA protein, and 78% amino acid identity with Arabidopsis SINAT5 protein. GhSH1a protein is a member of SINA (Seven in absentia) protein family which containing a highly conserved N-terminal C₃HC₄ Ring finger motif. N-terminal C₃HC₄ Ring finger motif of SINA protein is required to promote ubiquitin-proteasome pathway of target protein degradation, and C- terminal sequence plays a role in interaction with target protein.SINA gene was firstly identified in Drosophila. SINA protein is critically involved in regulating the cell fate decision of R7 photoreceptor cell in Drosophila eyes. Human SIAH1 is involved in cell apoptosis. Arabidopsis SINAT5 protein has ubiquitin-ligase E3 activity for attenuating auxin signals to regulate lateral root development. However, to our best knowledge, there is still no publication on the function of cotton SINA homologous protein. Moreover, auxin has critical roles in differential and development of cotton fiber and plant lateral root. According to the above analysis, GhSHla in our study may regulate the development and elongation of cotton lateral root or cotton fiber.PCR was conducted using 5'- and 3'-terminal primer of GhSH1a cDNA and cotton genomic DNA as template to amplify GhSH1a gene fragment. This fragment was sub-cloned into pGEM-T Easy vector to be sequenced. Sequencing result showed that GhSHla gene is 2631 bp in length. Compared to GhSHla cDNA nucleotide sequence, GhSHla gene contains 3...