5-HT1A and histamine H1 receptors in HeLa cells stimulate phosphoinositide hydrolysis and phosphate uptake via distinct G protein pools.

Published

Journal Article

Regulation of phosphate uptake was studied in a HeLa cell line after transfection with DNA encoding the human 5-HT1A receptor. In these cells, 5-HT stimulates sodium-dependent phosphate uptake via protein kinase C activation. Endogenous histamine H1 receptors (739 +/- 20 fmol/mg protein) were identified with [3H]pyrilamine. Histamine (i) stimulated phosphoinositide hydrolysis (EC50 = 8.6 +/- 4.1 microM), (ii) activated protein kinase C (2.4-fold increase in activity), and (iii) increased phosphate uptake (EC50 = 3.2 +/- 1.8 microM) by increasing maximal transport (Vmax(basal) = 6.2 +/- 0.3 versus Vmax(histamine) = 9.1 +/- 0.4) without changing the affinity of the transport process for phosphate. Prolonged treatment with 16 microM phorbol 12-myristate 13-acetate completely blocked protein kinase C activation and markedly attenuated the stimulation of phosphate uptake induced by histamine, establishing that 5-HT and histamine stimulate phosphate uptake through the common pathway of protein kinase C activation. The linkages of the histamine H1 and 5-HT1A receptors to G protein pools were assessed in two ways. (i) The stimulation of phosphoinositide hydrolysis, protein kinase C activity, and phosphate uptake associated with histamine were insensitive to pertussis toxin, whereas those associated with 5-HT were very sensitive to pertussis toxin. (ii) The stimulation of phosphoinositide hydrolysis, protein kinase C activity, and phosphate uptake induced by histamine and 5-HT were additive. These findings suggest that distinct receptor types can stimulate phosphoinositide hydrolysis, protein kinase C, and phosphate uptake in an additive fashion through distinct pools of G proteins in a single cell type.

Full Text

Duke Authors

Cited Authors

  • Raymond, JR; Albers, FJ; Middleton, JP; Lefkowitz, RJ; Caron, MG; Obeid, LM; Dennis, VW

Published Date

  • January 1, 1991

Published In

Volume / Issue

  • 266 / 1

Start / End Page

  • 372 - 379

PubMed ID

  • 1845968

Pubmed Central ID

  • 1845968

Electronic International Standard Serial Number (EISSN)

  • 1083-351X

International Standard Serial Number (ISSN)

  • 0021-9258

Language

  • eng