Characterization of Tumorigenic Proteins

The 17K, 84K, and 94K SV40 T antigens from SV40 permissive and transformed cells were analyzed by tryptic peptide mapping on ion exchange columns. The tryptic peptides were mapped relative to the SV40 DNA and to their known functions. The aminotermini of the 17K, 84K and 94K T antigens are identical. The 84K protein probably arises from the 94K T antigen by proteolytic cleavage of the 94K T antigen carboxyterminus. The 48K and 55K nonviral antigens, proteins immunoprecipitable by SV40 T antibody from SV40 permissive and transformed cells, were compared to the SV40 large T antigen and to each other by tryptic peptide mapping. The 48K and 55K nonviral antigens are not degradation products of the SV40 T antigens and at most are only slightly related to the SV40 T antigens. The 48K and 55K nonviral antigens are slightly related to each other, sharing about 3 methionine containing tryptic peptides. Four SV40 transformed human cell lines, one SV40 transformed mouse cell line, and eight SV40 transformed human/mouse somatic cell hybrid cell lines were examined for the expression of nonviral antigens. Differences were found in the patterns of expression of the nonviral antigens among the human cell lines, between the human and the mouse cell lines, and between the human/mouse somatic cell hybrid cell lines and the human lines from which they were derived. Two of the human cell lines expressed only a 55K nonviral antigen; two expressed both 55K nonviral antigen; two expressed both 55K and 52K nonviral antigens. The mouse cell line expressed both a 55K and a 48K nonviral antigen, except for one. The Balb IV-8 cell line expressed 55K and 52K nonviral antigens. By comparing the tryptic peptides fractionated on cation exchange columns of the nonviral antigens it was determined that: (1) The 48K nonviral antigen in human/mouse hybrids is encoded by a mouse chromosome. (2) The 52K nonviral antigen in the Balb IV-8 human/mouse hybrid is encoded by a mouse chromosome and is probably a precursor to the mouse 48K nonviral antigen. (3) The 55K nonviral antigen in the C57-VII-6 human/mouse hybrid is encoded by a human chromosome; while in the Balb IV-8 human/mouse hybrid the 55K protein band is encoded by a human chromosome and probably by a mouse chromosome also. (4) If the gene encoding the human nonviral antigen is located on a single chromosome, it is located on human chromosome 7.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biochemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Stitt, David Thomas

• Chemistry, Biochemistry

Language dc:language

eng

Identifier

(UMI)AAI8127706

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/67414