Dynamics of atrial natriuretic factor-guanylate cyclase receptors and receptor-ligand complexes in cultured glomerular mesangial and renomedullary interstitial cells.
The dynamics of the guanylate cyclase receptor of atrial natriuretic factor (GCA-ANF receptor) were investigated in cultured glomerular mesangial and renomedullary interstitial cells from the rat. In these cells, the GCA-ANF receptor did not mediate internalization and lysosomal hydrolysis of 125I-ANF1-28 and did not undergo ligand-induced endocytosis. Glomerular mesangial cells were able, however, to mediate internalization and lysosomal hydrolysis of 125I-ANF1-28 via clearance ANF (C-ANF) receptors and to promote rapid receptor-mediated internalization and lysosomal hydrolysis of 125I-(Sar1) angiotensin II. Radioligand specifically bound to surface GCA-ANF receptors was rapidly dissociated at 37 degrees C (k(off) greater than 0.8 min-1), with a Q10(30-37 degrees C) greater than 6. The dissociation was markedly slower at subphysiological temperatures (Q10(4-30 degrees C), 2-3) or in the presence of 0.5 mM amiloride. The results demonstrate that the GCA-ANF receptor, contrary to C-ANF receptors and most other polypeptide hormone receptors, is a membrane resident protein that does not mediate internalization and lysosomal hydrolysis of ligand. The termination of the interaction of ANF with GCA-ANF receptors results from a physiological process that leads to rapid dissociation of receptor-ligand complexes. The unique dynamics of GCA-ANF receptor-ligand complexes are likely to contribute importantly to stimulus-response homeostasis of ANF.
Koh
G Y
GY
Department of Physiology and Biophysics, Cornell University Medical College, New York, New York 10021.
Nussenzveig
D R
DR
Okolicany
J
J
Price
D A
DA
Maack
T
T
D000584:Amiloride / Q000494:pharmacology; D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D001667:Binding, Competitive; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000096:biosynthesis; D005920:Glomerular Mesangium / Q000166:cytology / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000378:metabolism*; D006868:Hydrolysis; D007679:Kidney Medulla / Q000166:cytology / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D017461:Receptors, Atrial Natriuretic Factor; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013696:Temperature
D011956:Receptors, Cell Surface; D000643:Ammonium Chloride; D000584:Amiloride; D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor; D006152:Cyclic GMP