Evolutionary variants of the mos gene

The occurence of members of mos oncogene family in the vertebrates genome has been studied with the help of highly labeled single-stranded DNA probes. These included subgenic v-mos clones as well as the unique sequence--specific recombinants from mos-related human locus gp5 and the K51 locus from rat genome. The probe from gp5 (mos pseudogene) interacts only with DNA of primates and of rodents. On the other hand, mos gene and the gene from K51 locus are present in all vertberates tested. Recent duplication of the main mos gene in Artiodactyla and Perissodactyla orders of mammals was identified. The persistence of K51 and mos genes during evolution indicates their importance. The segregation of three mos-related genes in human-hamster hybrids points to their location on different human chromosomes.     

Relationship between the major protein kinase C substrates acidic 80-kDa protein-kinase-C substrate (80K) and myristoylated alanine-rich C-kinase substrate (MARCKS). Members of a gene family or equivalent genes in different species.

Two major protein-kinase-C (PKC) substrates have been described in the literature; an 87-kDa bovine and human PKC substrate, called MARCKS, and an acidic 80-kDa PKC substrate, isolated from rat brain and Swiss 3T3 cells, termed 80K. Since there is only 66-74% sequence similarity between MARCKS and 80K, we have further investigated their relationship in this study. Southern-blot experiments with gene-specific probes demonstrated the presence of the 80K, but not MARCKS, gene in the mouse genome. Furthermore, polymerase-chain-reaction (PCR) analyses using three pairs of primers that specifically recognise either 80K, MARCKS or conserved sequences of both genes, revealed the presence of only the 80K gene in the mouse and rat genomes and only the MARCKS gene in the bovine and human genomes with mRNA expression in the corresponding brain tissues. Northern-blot analysis of a variety of tissues indicated that both 80K and MARCKS have similar patterns of expression. Most components of signal-transduction pathways are present in multiple molecular isoforms as members of a gene family. In contrast, the findings presented in this study indicate that rodent 80K and bovine and human MARCKS are not distinct members of a gene family, but represent the equivalent substrates in different species.     

Identification of a protein product of a novel human gene SON and the biological effect upon administering a changed form of this gene into mammalian cells

We have investigated the functional activity of human son gene, that possesses the homology to mos and myc genes. Specific antibodies (antiserum) were raised to synthetic peptide, that corresponds to son-protein 943-963 amino acid residues. With this antiserum the presence of son-protein was showed in lysates of cultured human cells transformed by adenovirus type 5, RAT 2 cells and primary human embryonic fibroblasts. son-Protein molecular weight (92 kDa) was determined by the method of electrophoresis in SDS-polyacrylamide gel. Thus, it was shown the presence of son gene protein in animal and human cells. To determine a possible son gene role in mammalian cells we have cloned the 3' part (2667 b.p.) of son cDNA in retroviral vector pPS-3-neo. Transformed cells of different lines were selected. A large portion of this cells changed their morphology. New protein product (120 k), that reacted with antiserum to son specific peptide, was found together with p92son in these clones.     

Segments of the human genome, containing analogs of oncogenes and retrovirus genes. 4. Primary structure of the mos-related AO section of the ORAgp5 locus

AO region (884 b.p.) of ORAgp5 locus has been sequenced and proved to contain mos-related regions, as well as fragments structurally similar to proretroviral elements and Alu repeats. The data obtained are in accordance with earlier hypotheses on retroviral involvement in mos gene family generation and the role of Alu repeat insertion in the inactivation of mos-related genes. Molecular hybridisation studies showed the structural conservation of the segment in ORAgp5 locus comprising the AO region among higher primates. These data indicate that AO region of ORAgp5 was formed not later than 65-70 MYR ago and that the present structure of this region was kept during last 50 MYR.