Biomedical subjects

J DeAnda

Publications and source records attributed to J DeAnda.

4 recordsLinked to original sources

PubMed1988

Immunization against the polyoma tumor-specific transplantation antigen (TSTA) with polyoma T-antigens.

The relationship between the polyoma virus tumor-specific transplantation antigen (TSTA) and 2 of the virus proteins coded from the early region of polyomavirus was investigated. Mice were immunized with small T antigen and a truncated mutant of middle T antigen, both purified from genetically engineered Escherichia coli. The 2 proteins induced protective immunity against polyomavirus-induced tumors, but not against non-polyoma tumors, indicating that one or more of the polyoma T antigens are directly involved in a TSTA function.

Animals↗

PubMed1988

Cellular proteins that associate with the middle and small T antigens of polyomavirus.

We have used two-dimensional gel electrophoresis to analyze in more detail the cellular proteins which associate with the middle and small tumor antigens (MT and ST, respectively) of polyomavirus. Proteins with molecular masses of 27, 29, 36, 51, 61, 63, and 85 kilodaltons (kDa) that specifically coimmunoprecipitated with MT were identified on these gels. The 36-, 51-, 61-, 63-, and 85-kDa proteins are probably the same as the proteins of similar sizes previously reported by a number of groups, whereas the 27- and 29-kDa proteins represent proteins that are heretofore undescribed. The 27- and 29-kDa proteins were abundant cellular proteins, whereas the others were minor cellular constituents. The association of each of these proteins with MT was sensitive to one or more mutations in MT that rendered it transformation defective. The association of the 85-kDa protein was the most sensitive indicator of the transformation competence of MT mutants. In addition, the 85-kDa protein was the only associated protein whose association with MT changed consistently in parallel with MT-associated phosphatidylinositol kinase activity. Furthermore, the fraction of the 85-kDa protein which was found associated with the MT complex contained 15 to 20% of its phosphate content on tyrosine. The 36- and 63-kDa proteins complexed with both polyomavirus MT and ST and comigrated on two-dimensional gels with two simian virus 40 ST-associated proteins originally described by Rundell and coworkers (K. Rundell, E. O. Major, and M. Lampert, J. Virol. 37:1090-1093, 1981). None of the other MT-associated proteins associated significantly with ST.

Antigens, Polyomavirus Transforming↗

PubMed1983

Primary structure of the immI immunity region of bacteriophage P22.

The DNA sequence of the immI immunity region of bacteriophage P22 has been determined. This region includes the ant gene, which encodes the P22 antirepressor protein, and the mnt and arc genes, which encode proteins that negatively regulate antirepressor synthesis. We have purified antirepressor protein and selected tryptic peptides of antirepressor, and have determined the amino terminal sequences and amino acid composition of these molecules. These data, in combination with the DNA sequence, locate the ant gene and define the complete amino acid sequence of antirepressor (300 residues). The mnt and arc genes have been located by sequencing the mnt-am343 and arc-amH1605 mutations. The Mnt and Arc proteins are predicted to be small, basic polypeptides that are homologous in amino acid sequence. The Mnt protein also shows significant sequence homology with the lambda Cro protein. The arc and ant genes are transcribed rightward from the Pant promoter, while mnt is transcribed leftward from a promotor that may overlap Pant. The Mnt protein apparently acts by binding to an operator site located immediately adjacent to the startpoint of Pant transcription.

Amino Acid Sequence↗

PubMed1983

The lambda and P22 phage repressors.

The lambda cI repressor and the P22 c2 repressor contain two structural domains. In both proteins, the N-terminal domains mediate operator recognition and positive control of transcription, and the C-terminal domains mediate subunit oligomerization and recognition of the recA protein. In some cases, structural, biochemical, and genetic studies implicate particular repressor side chains in these processes.

Amino Acid Sequence↗