Cloning and characterization of a novel soybean receptor-like protein kinase gene GmRLCK.

Protein kinases play key roles in transduction of both environmental and developmental signals in higher plants. Here reported full-length cDNA cloning and preliminary structural and functional analysis of a novel soybean receptor-like protein kinase (RLK) gene (GenBank Accession No.AY687390). The deduced protein product of this gene contains a transmembrane region, an intracellular catalytic domain possessing serine/threonine kinase activity, and an extracellular domain which lacks the N-terminus signal peptide. Bioinformatic analyses revealed highly similarity between this soybean gene and a group of the Arabidopsis RLK genes which all lack of N-terminus signal sequence and belong to RLCK subfamily. Thus, it was designated GmRLCK. Some residues of GmRLCK that showed high probability to be phosphorylated were also predicted. RT-PCR analysis revealed higher expression levels of GmRLCK in soybean cotyledons, roots, flowers and young pods; whereas lower expression levels were detected in radicles, stems and mature leaves at vegetative stage. Phylogeny analysis suggested that GmRLCK was more close to and might have a common ancestor with several senescence-associated RLKs.