Calcium entry is required for fundamental processes in non-excitable cells. In human T cells (Jurkats), calcium influx is involved in activation and in murine erythroleukemia cells (MELC) in cellular differentiation. The objectives of the proposed research are: 1) to clone and express calcium channels from non-excitable cells (MELC and Jurkats); 2) to functionally characterize the cloned channels; and 3) to determine the role of such channels in the control of proliferation and induced differentiation in non-excitable cells. Preliminary studies in our laboratory indicate that MELC and Jurkats express calcium channels which are distinct from, but homologous to, the cardiac dihydropyridine receptor (DHPR). Our evidence for this includes: 1) the isolation of partial cDNAs encoding putative calcium channels expressed in MELC and Jurkats; 2) sequence analysis of these cDNAs demonstrating several additions, deletions and insertions compared to the DHPR, in particular the lack of the IIIS1 putative transmembrane region; 3) Northern blot analysis indicating that the putative calcium channel mRNAs are expressed at significant levels in MELC and Jurkats. We propose: 1) to clone and express complete cDNAs encoding calcium channels from MELC and Jurkat; 2) to functionally characterize the cloned MELC and Jurkat calcium channels in terms of blockers, activators, voltage-sensitivity, and ionic basis of channel function using Xenopus oocytes injected with in vitro transcribed RNA; 3) to examine the effects of agents which modulate calcium channel function on induced differentiation in MELC and Jurkats respectively; 4) to transfect MELC and Jurkats with sense and antisense cDNAs to establish lines which over and under express the calcium channels; 5) to characterize calcium influx in these cell lines during MELC differentiation and T cell activation. The significance of these studies will be the characterization of the structure and function of calcium channels expressed in non-excitable cells. These calcium channels may be involved in fundamental cellular functions, including erythroid cell differentiation and T cell activation.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
1R01NS029814-01A1
Application #
3416706
Study Section
Physiology Study Section (PHY)
Project Start
1992-06-01
Project End
1996-05-31
Budget Start
1992-06-01
Budget End
1993-05-31
Support Year
1
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Mount Sinai School of Medicine
Department
Type
Schools of Medicine
DUNS #
City
New York
State
NY
Country
United States
Zip Code
10029
Ondrias, K; Marx, S O; Gaburjakova, M et al. (1998) FKBP12 modulates gating of the ryanodine receptor/calcium release channel. Ann N Y Acad Sci 853:149-56
Gutstein, D E; Marks, A R (1997) Role of inositol 1,4,5-trisphosphate receptors in regulating apoptotic signaling and heart failure. Heart Vessels Suppl 12:53-7
Poon, M; Marx, S O; Gallo, R et al. (1996) Rapamycin inhibits vascular smooth muscle cell migration. J Clin Invest 98:2277-83
Maki, T; Gruver, E J; Davidoff, A J et al. (1996) Regulation of calcium channel expression in neonatal myocytes by catecholamines. J Clin Invest 97:656-63
Marks, A R (1996) Cellular functions of immunophilins. Physiol Rev 76:631-49
Ondrias, K; Brillantes, A M; Scott, A et al. (1996) Single channel properties and calcium conductance of the cloned expressed ryanodine receptor/calcium-release channel. Soc Gen Physiol Ser 51:29-45
Kaftan, E; Marks, A R; Ehrlich, B E (1996) Effects of rapamycin on ryanodine receptor/Ca(2+)-release channels from cardiac muscle. Circ Res 78:990-7
Patton, W F; Erdjument-Bromage, H; Marks, A R et al. (1995) Components of the protein synthesis and folding machinery are induced in vascular smooth muscle cells by hypertrophic and hyperplastic agents. Identification by comparative protein phenotyping and microsequencing. J Biol Chem 270:21404-10
Kobrinsky, E; Ondrias, K; Marks, A R (1995) Expressed ryanodine receptor can substitute for the inositol 1,4,5-trisphosphate receptor in Xenopus laevis oocytes during progesterone-induced maturation. Dev Biol 172:531-40
Marx, S O; Jayaraman, T; Go, L O et al. (1995) Rapamycin-FKBP inhibits cell cycle regulators of proliferation in vascular smooth muscle cells. Circ Res 76:412-7

Showing the most recent 10 out of 17 publications