Abstract
We cloned a cDNA encoding a receptor-like protein kinase, PnLRK1 ((Populus nigra var. italica leucine-rich repeat receptor kinase 1), from a shoot cDNA library of lombardy poplar. The cDNA is about 2.7 kbp in length and contains an open reading frame encoding the PnLRK1 protein of 856 amino acids. The N-terminus of PnLRK1 has a potential signal peptide. This is followed by a putative extracellular domain consisting of 14 leucine-rich repeats (LRRs). The C-terminal catalytic domain of PnLRK1 has twelve subdomains, which are conserved in the protein kinase family. A putative hydrophobic transmembrane domain is localized between the LRRs domain and the catalytic domain. The PnLRK1 gene was expressed in leaves, stems and apical buds of lombardy poplar; trace amounts of the mRNA were detectable in roots.
