Preliminary Study On The Mechanisms For Nuclear Translocation Of KGF-2 And BFGF

KGF-2 and bFGF are two members of fibroblast growth factor family . The biological activities of KGF-2 and bFGF include cell proliferation and differentiation, angiogenesis, tumorigenesis, wound healing and embryonic development, etc.But their mechanisms remain unclear. We have performed a series of experiments on the proteins potentially interacted with KGF-2 and bFGF by means of gene recombination , yeast two-hybrid system, mammalian two-hybrid system and cell culture etc. The results included the following four parts:1.The genes encoding human KGF-2 and bFGF were isolated by PCR from human fetal hepatic cDNA library and confirmed by sequence analysis.2. Yeast two-hybrid system was used to screen the proteins interacting with KGF-2 and bFGF.Vector pAS2-1-KGF~2 and pAS2-1-bFGF had been constructed and transfered into yeast host Y190, respectively. KGF-2 and bFGF have no self-activating action. Two genes,which encode proteins interacting with KGF-2, were obtained by screening human fetal hepatic cDNA library.By homology comparison, they were identified as PR02605 and human ribosomal protein L22(RPL22). PRL22 has a classical nuclear localization sequence(NLS) in its N-terminal. Interacting with RPL22 may be one pathway of KGF-2 to enter nucleus.3. The interaction between KGF-2 and RPL22 was identified in COS-7 cell line by mammalian two-hybrid system.4. In NIH/3T3 cell, the expression level of RPL22 gene was increasedby stimulation with exogenous KGF-2 and bFGF, respectively.