Isolation and functional characterization of the C-terminus of rice phosphatidylinositol 4-kinase in vitro
A partial rice (Oryza sativa L.) cDNA clone, OsPI4K1c, was isolated through screening of a cDNA library constructed from tillering materials. OsPI4K1c encoded a peptide of 608 amino acids with a calculated molecular mass of 68.4 kDa. The OsPI4K1c peptide shared high homology and possessed the highly conserved domains present in most isolated cloned PI4-kinases, i.e. a lipid kinase unique (LKU) domain and a catalytic (CAT) domain. A region with similarity to pleckstrin homology (PH) domain was present in OsPI4K1c as well. Further comparison with genomic sequences in databases revealed that OsPI4K1c is located at the 3'-end of a putative rice PI 4-kinase coding gene OsPI4K1, and its coding region corresponded to the C-terminal half of OsPI4K1 protein. Twelve exons (49-562 bp in size) and 11 introns (77-974 bp in size) were identified in OsPI4K1c. The recombinant protein expressed in Escherichia coli phosphorylates phosphatidylinositol at the D4 position of the inositol ring. OsPI4K1 transcript levels were detected in a low but constitutive manner in shoot, stem, leaf, spike and root tissues and did not change upon treatment with different hormones, calcium and jasmonic acid (JA). However, treatment with salicylic acid (SA) elevated the mRNA level of the OsPI4K1 gene, which suggested the involvement of OsPI4K1 in wounding responses.
作 者： XIANG FENG KONG ZHI HONG XU HONG WEI XUE 作者单位： National Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Science (SIBS), The Chinese Academy of Sciences; Partner Group of Max Planck-Institute of Molecular Plant Physiology (MPI-MP) on 刊 名： 细胞研究(英文版) ISTIC SCI 英文刊名： CELL RESEARCH 年，卷(期)： 2003 13(2) 分类号： Q5 关键词： Oryza sativa phosphatidylinositol 4-kinase