Molecular cloning and characterization of GhlecRK, a novel kinase gene with lectin-like domain from Gossypium hirsutum

A novel gene encoding a lectin-like protein kinase was cloned from the upland cotton ( Gossypium hirsutum ) through cDNA library screening. This gene (named as Ghlecrk ; GenBank accession number: AY487461) had a total length of 2233 bp with an open reading frame of 1926 bp, and encoded a predicted polypeptide of 641 amino acids with a molecular weight of 71.16 kDa. The GhLecRK protein shared 73, 65, 64 and 59% identity with other lectin-like kinase proteins isolated from A. thaliana (At3g53810, At2g37710, At3g55550) and Populus nigra (PnLPK) at amino acid level, respectively. Southern blot analysis showed that GhLecRK belonged to a multi-copy gene family. Expression patterns revealed that GhLecRK was enriched in the developing boll (six days post anthesis, 6DPA) and shoot, but low in the root and stem and no expression in the leaf. The domains analysis showed that GhlecRK protein possessed many activating sites/domains including ATP-binding sites, a transmembrane region, a lectin-like domain and a kinase domain. These results indicate that GhlecRK is a lectin-like membrane protein that may play an important role in the phase of fiber development.