of Work: In preliminary studies reported previously the HIV viral coat protein, gp120, inhibited voltage-dependent calcium channels in a rat pituitary tumor cell line (GH4C1). We are investigating the possibility that gp120 acts through a G-protein coupled chemokine receptor to stimulate protein phosphatase activity, as we have demonstrated for other G-protein coupled receptors in GH cells. To obtain a defined and reliable source of gp120, we subcloned a secretion-directed cDNA sequence encoding the HIV coat protein, GP120 strin MN, with mammalian codons (Haas et al., 1996 Current Biology 6:315) into the mammalian exression vector, PCI-Neo (Promega Biotech) and transfected it into HelaS3 cells, a cervical carcinoma line. A subclone of HelaS3 with high stable GP120 expression was isolated, and the protein was purified from the conditioned medium. GP120 was purified by a single step purificationon a GP120 antibody affinity column by elution with high magnesium. We are testing the effects of this recombinant protein on ion channel activity in GH4C1 cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Intramural Research (Z01)
Project #
1Z01ES080052-04
Application #
6106778
Study Section
Special Emphasis Panel (LST)
Project Start
Project End
Budget Start
Budget End
Support Year
4
Fiscal Year
1998
Total Cost
Indirect Cost
City
State
Country
United States
Zip Code
Storey, Nina M; Gomez-Angelats, Mireia; Bortner, Carl D et al. (2003) Stimulation of Kv1.3 potassium channels by death receptors during apoptosis in Jurkat T lymphocytes. J Biol Chem 278:33319-26