Molecular characterization of the NelF2B beta gene encoding a putative elF2B beta-subunit in Nicotiana tabacum

The NeIF2B beta cDNA encoding beta -subunit of the translation initiation f actor 2B (eIF2B-beta) was identified from Nicotiana tabacum through protein interaction with PRK1, a reproductive-organ-specific receptor-like kinase (Park et al, 2000), The eIF2B is a guanine nucleotide-exchange protein that consists of five subunits, which function in the regulation of translation in eukaryotic cells, The NeIF2B beta that shows a high homology in the ami no acid sequence with other beta -subunits ;lso exhibits sequence similarit y to alpha and delta subunits of eIF2B from yeast and animals. The NeIF2B b eta gene was expressed in all of the tissues examined, but the mRNA level w as higher in reproductive tissues than in vegetative tissues. During anther development, the NeIF2B beta mRNA was detected in all stages with a slight ly higher level in the earliest stage. The NeIF2B beta -GFP fusion protein was mainly localized in the cytosol.