The overall goal of this project is to understand the molecular mechanisms by which heavy metal ions affect gene expression in human cells. Trace metal ions like Zn and Cu are necessary for proper function, growth and development of all living organisms, yet when present in high concentration they can lead to adverse effects. On the other hand, metals like Cd and Hg have no obvious biological role and are significant environmental toxins, teratogens and possibly carcinogens. The long term effects of imbalanced Zn and Cu metabolism and exposure to Cd and Hg are likely to be mediated by the interactions of these metal ions with the gentic apparatus. To understand how these metal ions affect the human transcriptional apparatus we have been studying the structure and expression of the human metallothionein (MT) gene family, used as a model. The transcription of these genes is induced by heavy metal responsive elements via a putative metal responsive factor (MRF) that binds to the metal responsive elements (MRE's), four of which are present in the hMT-IIA promoter. We plan to isolate the MRF, determine a partial amino-acid sequence, raise specific antisera and isolate a cDNA clone encoding this factor. The complete structure of the factor will be determined by sequencing the cDNA. Site-specific mutagenesis will be used to study its mechanism of action. Similarly, we will isolate other factors that are responsible for the basal activity of the hMT-IIA promoter and for its induction by growth factors and tumor promoters. Their corresponding cDNAs will be isolated as well, and used to determine the structure of the factors. The interactions between the various factors which serve to regulate the expression of the hMT-IIA gene will be studied in a reconstituted in-vitro transcription system. In addition, we will examine the effect of heavy metal ions on the activity of regulatory proteins that use the """"""""Zn binding finger motif"""""""" for recognition of specific DNA sequence. For these experiments two well characterized proteins, TFIIIA and the glucocorticoid receptor, will be used as a model. The effect of Cd and Hg on their specific and non-specific DNA binding activities will be determined in order to reach a better understanding of the mechanisms by which these toxic ions can interfere with the function of the transcriptional apparatus. Completion of these studies will provide us with the required biochemcial basis for understanding the effects of beneficial and toxic heavy metal ions on the human transcriptional apparatus.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
5R01ES004151-04
Application #
3252132
Study Section
Molecular Biology Study Section (MBY)
Project Start
1986-01-01
Project End
1993-03-31
Budget Start
1989-04-01
Budget End
1990-03-31
Support Year
4
Fiscal Year
1989
Total Cost
Indirect Cost
Name
University of California San Diego
Department
Type
Schools of Medicine
DUNS #
077758407
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Sakurai, Toshiharu; Kudo, Masatoshi; Umemura, Atsushi et al. (2013) p38? inhibits liver fibrogenesis and consequent hepatocarcinogenesis by curtailing accumulation of reactive oxygen species. Cancer Res 73:215-24
Cho, Ik-Hyun; Hong, Jinpyo; Suh, Eun Cheng et al. (2008) Role of microglial IKKbeta in kainic acid-induced hippocampal neuronal cell death. Brain 131:3019-33
Naugler, Willscott E; Sakurai, Toshiharu; Kim, Sunhwa et al. (2007) Gender disparity in liver cancer due to sex differences in MyD88-dependent IL-6 production. Science 317:121-4
Temkin, Vladislav; Karin, Michael (2007) From death receptor to reactive oxygen species and c-Jun N-terminal protein kinase: the receptor-interacting protein 1 odyssey. Immunol Rev 220:8-21
Solinas, Giovanni; Vilcu, Cristian; Neels, Jaap G et al. (2007) JNK1 in hematopoietically derived cells contributes to diet-induced inflammation and insulin resistance without affecting obesity. Cell Metab 6:386-97
Gallagher, Ewen; Enzler, Thomas; Matsuzawa, Atsushi et al. (2007) Kinase MEKK1 is required for CD40-dependent activation of the kinases Jnk and p38, germinal center formation, B cell proliferation and antibody production. Nat Immunol 8:57-63
Gallagher, Ewen; Gao, Min; Liu, Yun-Cai et al. (2006) Activation of the E3 ubiquitin ligase Itch through a phosphorylation-induced conformational change. Proc Natl Acad Sci U S A 103:1717-22
Scheuner, Donalyn; Patel, Rupali; Wang, Feng et al. (2006) Double-stranded RNA-dependent protein kinase phosphorylation of the alpha-subunit of eukaryotic translation initiation factor 2 mediates apoptosis. J Biol Chem 281:21458-68
Labuda, Tord; Christensen, Jan Pravsgaard; Rasmussen, Susanne et al. (2006) MEK kinase 1 is a negative regulator of virus-specific CD8(+) T cells. Eur J Immunol 36:2076-84
Tuncman, Gurol; Hirosumi, Jiro; Solinas, Giovanni et al. (2006) Functional in vivo interactions between JNK1 and JNK2 isoforms in obesity and insulin resistance. Proc Natl Acad Sci U S A 103:10741-6

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