Biological Function Of The Human The Protein Ntkl-bp1 And Its Interacting Protein

Followed the human genome project, the post-genomic era is coming. The function research of novel proteins becomes a hot spot. A novel human gene hNTKL-BP1 was cloned from placenta cDNA library in our laboratory. This study was designed to investigate the function of hNTKL-BP1 and the protein interacting with hNTKL-BP1.Through RT-PCR, we found hNTKL-BP1 is widely expressed in 16 kinds of adult tissues. In heart, liver, pancreas, spleen, thymus and prostate, the expression of hNTKL-BP1 is high. Through Northern Blot, two transcripts of hNTKL-BP1 were observed. We cloned the small one, hNTKL-BP2, from fetal liver cDNA library. We compared the structure and the sub-cellular location between hNTKL-BP1 and hNTKL-BP2. They have different C terminus and different sub-cellular location, which indicates they have different function. hNTKL-BP1 has some homology with members of Dynactinl family, but the complement test in yeast failed. hNTKL-BP1 can not complement the function of nip 100, which is a member of Dynactinl family in yeast. But the expression of hNTKL-BP1 inhibited the proliferation of yeast cells. Furthermore, the colony formation experiment, the result of cell growth curve and in vivo tumorigenicity assay all showed over-expression of hNTKL-BP1 suppress the growth of liver cancer cell SMMC 7721 and the tumor formation. To further address the mechanisms underlying the decreased cell population after hNTKL-BP1 overexpression, we performed FACS scan. The results showed that the excessive amounts of hNTKL-BP1 proteins could decrease cell proliferation by interfering the G2/M progression. Through the Atlas System assay, 3 genes, which can promote the cell proliferation, were found downregulated after the overexpression of hNTKL-BP1. Our results suggest that hNTKL-BP1 protein might modulate cell cycle progression as a cell cycle regulation factor and its abnormal expression will affect the cell proliferation. Our research about hNTKL-BP1 may represent a new approach for anti-cancer therapy. Further research of hNTKL-BPl is promising.Through the yeast two-hybrid system, we obtained two proteins as the hNTKL-BP1 interacting protein: hNTKL and hPirh2. hNTKL has a kinase-like domain in the N-terminus. Through the interaction with hNTKL-BP1, hNTKL may affect the phosphorylation of hNTKL-BP1. With the intact RING finger domain,...