Defects in PTEN, a tumor suppressor, have been found in cancers arising in a variety of human tissues. To elucidate the tumor-suppressive function of this gene, we have been analysing expression profiles of cancer cells after introduction of exogenous PTEN. Those experiments identified 99 candidate genes that were transcriptionally transactivated. Among them, we report here the further analyses of eight genes, EGR2/Krox-20, BPOZ, APS, HCLS1/HS1, DUSP1/MKP1, NDRG1/Drg1/RTP, NFIL3/E4BP4, and a novel gene (PINK1, PTEN-induced putative kinase). Expression of six of them (PINK1, EGR2, HCLS1, DUSP1, BPOZ, and NFIL3) was decreased in ovarian tumors compared with corresponding normal tissues. Colony-formation assays using plasmid clones designed to express each gene indicated that EGR2 and BPOZ were able to suppress growth of cancer cells significantly; in particular, cancer-cell lines stably expressing BPOZ grew more slowly than control cells containing mock vector. Flow cytometry suggested that over-expression of BPOZ inhibited progression of the cell cycle at the G(1)/S transition. Anti-sense oligonucleotides for BPOZ or EGR2 effectively inhibited their expression, and cell growth was accelerated. Therefore both genes appear to be novel candidates as mediators of the PTEN growth-suppressive signaling pathway.
A novel human gene containing an ankyrin repeat and BTB/POZ domains (BPOZ) was isolated from a human leukocyte cDNA library. The cDNA sequence contains an open reading frame of 1434 bp that encodes 478 amino acid residues with a predicted molecular mass of 53.9 kDa. Sequence pattern analysis shows that BPOZ contains an N-terminal ankyrin repeat, a bipartite nuclear localization signal and two BTB/POZ domains. Using semiquantitative RT-PCR, the BPOZ transcript was found to be ubiquitously expressed in all fetal tissues examined (heart, brain, liver, and kidney) suggesting that BPOZ is involved in basic cellular function. Low expression of BPOZ in adult tissues (normal and hypertrophic heart) suggests that BPOZ mRNA is developmentally regulated and may play a role in developmental processes. Chromosomal localization by radiation hybrid mapping revealed that this gene is localized between D3S1269 and D3S3606 markers corresponding to the region of chromosome 3q21, a region frequently associated with leukemia. It is thus suggested that BPOZ may be functionally involved in protein-protein interaction, perhaps in forming protein complexes, and may have an important role in normal development and in the development of leukemia.
Protein involved in the biosynthesis of proteins from mRNA molecules. This process, called translation, is carried out by ribosomes, where activated amino acids are added to the nascent polypeptide chain.
Protein that associates with ribosomes cyclically during the elongation phase of protein synthesis, and catalyze formation of the acyl bond between the incoming amino-acid residue and the peptide chain.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.
My favorites 
My labels 
Login
