POSTER NO: 243

The Characteristics of a Novel Candidate Tumor Suppressor PIP29

¹Lusheng Xu, ¹Xin Zhang, ¹Zhihong Cheng, ¹Jian Qu, ²Shangzhi Huang, ¹Zeguang Han
¹Chinese National Human Genome Center at Shanghai, No.351, Guo Shou Jing Road, Zhang-jiang Hi-Tech Park, Pudong, Shanghai, 201203, P.R. China, ²Peking Union Medical College and Chinese Academic of Medical Science, No.5 Dongdan Santiao, Beijing, 100005, P.R. China

ING1, a human tumor suppressive gene, has been found to be involved in regulation of cell growth, senescence and apoptosis by interacting with p53. Recently, we have isolated a novel human gene PIP29, which shares 32% identity to human p33ING1b. The full-length cDNA of PIP29 has 1374bp and encodes 248 amino acid residues. Bioinformatics analyses showed this protein contains a nuclear location signal (NLS) and a PHD domain in its C-terminal. Northern blot revealed that PIP29 is expressed in many tissues, highly in skeletal muscle, heart, placenta and kidney. Indirect immunofluorescence displayed PIP29 protein is located in the nucleus. Overexpression of PIP29 in stable transfected HepG2 cells could inhibit the cell growth and arrest cells in G1 phase. The GST pull-down assay indicated that PIP29 protein can interact with p53 in vitro but the interaction remains to be confirmed in vivo. Mammalian one-hybrid experiments showed that PIP29 can stimulate the expression of the reporter gene and suggested that PIP29 might be a transcriptional factor. The data we show here implied that PIP29 might involve in cell cycle control and transcriptional regulation.