Recently our laboratory has demonstrated that the 3'-untranslated region (3'-UTR) of the cDNA of the bovine lymphokine interleukin- 2 (blL-2) acts as a lymphoid cell-specific gene regulatory element in vivo. Within the 3'-UTR we have identified a highly conserved nucleotide sequence motif, (TATT)n, that is also found in the 3'- UTRs of many other transiently expressed immunoregulatory genes of mammals. We have furthermore demonstrated that this conserved A/T- rich motif in blL-2 serves multiple functions in stimulated bovine lymphocytes, both at the DNA and RNA levels. At the chromosomal level the motif acts as the specific binding site for a nonhistone protein, HMG-1, and at the RNA level the conserved (UAUU)n cognate motif of the mRNA acts as a POSTTRANSCRIPTIONAL REGULATORY ELEMENT that determines the stability and selective degradation of blL-2 mRNA by serving as the recognition site for a specific nuclease(- s). Additionally, we have now isolated (from stimulated bovine lymphocytes) a large number of different UNKNOWN cDNA clones that contain the conserved motif in their 3'-UTRs and have many features suggesting that they may represent an as of yet unidentified group of lymphokine or growth factor-like genes. Furthermore, we have demonstrated that the cellular expression of the mRNAs of several of these unknown immunoregulatory genes are specifically modulated in lymphocytes infected with BOVINE LEUKEMIA VIRUS (BLV), AN HTLV- LIKE RETROVIRUS. The HYPOTHESIS TO BE TESTED by the proposed research is that these lymphokine gene regulatory mechanisms we have observed for the bovine system ARE ALSO GENERALLY APPLICABLE TO THE HUMAN LYMPHOKINE AND IMMUNOREGULATORY GENES CONTAINING THE CONSERVED A/T-MOTIFS AND THAT INFECTION OF HUMAN LYMPHOID CELLS BY HTLV AND HIV RETROVIRUSES MAY SPECIFICALLY MODULATE THE EXPRESSION OF THIS CLASS OF CELLULAR GENES.
SPECIFIC AIMS of the research are to: (1) Investigate the possible in vivo posttranscriptional gene regulatory role of the 3'-UTRs of several REPRESENTATIVE lymphokine and immunoregulatory genes of human lymphocytes, including lL's-1, -2, INF-gamma, TNF and GM-CSF. (2) Characterize members of a group of CURRENT UNKNOWN immune-induced bovine cDNA clones containing the A/T-motif, particularly those clones who in vivo cellular genes are known to be specifically modulated by infection of lymphocytes by BLV. ISOLATE, CHARACTERIZE AND DETERMINE THE EXPRESSION OF A HOMOLOGOUS GROUP of cDNA clones from normal, HTLV-infected and HIV- infected HUMAN LYMPHOCYTES. (3) Directly investigate the role of THE TRANS-ACTIVATING tat PROTEINS OF HTLV-1 in the in vivo activation and modulation of the CONSTELLATION OF TRANSIENTLY EXPRESSED LYMPHOKINE AND IMMUNOREGULATORY GENES containing the 3'- UTR conserved A/T sequence motifs.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI026356-01
Application #
3140137
Study Section
(SSS)
Project Start
1988-09-30
Project End
1991-08-31
Budget Start
1988-09-30
Budget End
1989-08-31
Support Year
1
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Washington State University
Department
Type
Schools of Arts and Sciences
DUNS #
041485301
City
Pullman
State
WA
Country
United States
Zip Code
99164
Holth, L T; Thorlacius, A E; Reeves, R (1997) Effects of epidermal growth factor and estrogen on the regulation of the HMG-I/Y gene in human mammary epithelial cell lines. DNA Cell Biol 16:1299-309
Ogram, S A; Reeves, R (1995) Differential regulation of a multipromoter gene. Selective 12-O-tetradecanoylphorbol-13-acetate induction of a single transcription start site in the HMG-I/Y gene. J Biol Chem 270:14235-42
Reeves, R; Nissen, M S (1995) Cell cycle regulation and functions of HMG-I(Y). Prog Cell Cycle Res 1:339-49
Nissen, M S; Reeves, R (1995) Changes in superhelicity are introduced into closed circular DNA by binding of high mobility group protein I/Y. J Biol Chem 270:4355-60
Siino, J S; Nissen, M S; Reeves, R (1995) Replacement of conserved threonines by alanine residues in high mobility group protein HMG-I(Y): effect on DNA binding affinity. Biochem Biophys Res Commun 207:497-507
Reeves, R; Nissen, M S (1993) Interaction of high mobility group-I (Y) nonhistone proteins with nucleosome core particles. J Biol Chem 268:21137-46
Friedmann, M; Holth, L T; Zoghbi, H Y et al. (1993) Organization, inducible-expression and chromosome localization of the human HMG-I(Y) nonhistone protein gene. Nucleic Acids Res 21:4259-67
Friedmann, M; Nissen, M S; Hoover, D S et al. (1992) Characterization of the proto-oncogene pim-1: kinase activity and substrate recognition sequence. Arch Biochem Biophys 298:594-601
Fashena, S J; Reeves, R; Ruddle, N H (1992) A poly(dA-dT) upstream activating sequence binds high-mobility group I protein and contributes to lymphotoxin (tumor necrosis factor-beta) gene regulation. Mol Cell Biol 12:894-903
Nissen, M S; Langan, T A; Reeves, R (1991) Phosphorylation by cdc2 kinase modulates DNA binding activity of high mobility group I nonhistone chromatin protein. J Biol Chem 266:19945-52

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