Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Histamine Treatment Induces Rearrangements of Orthogonal Arrays of Particles (OAPs) in Human AQP4-Expressing Gastric Cells

Monica Carmosino, Giuseppe Procino, Grazia Paola Nicchia, Roberta Mannucci, Jean-Marc Verbavatz, Renèe Gobin, Maria Svelto and Giovanna Valenti
The Journal of Cell Biology
Vol. 154, No. 6 (Sep. 17, 2001), pp. 1235-1243
Stable URL: http://www.jstor.org/stable/1620706
Page Count: 9
  • More info
  • Cite this Item
Histamine Treatment Induces Rearrangements of Orthogonal Arrays of Particles (OAPs) in Human AQP4-Expressing Gastric Cells
Preview not available

Abstract

To test the involvement of the water channel aquaporin (AQP)-4 in gastric acid physiology, the human gastric cell line (HGT)-1 was stably transfected with rat AQP4. AQP4 was immunolocalized to the basolateral membrane of transfected HGT-1 cells, like in native parietal cells. Expression of AQP4 in transfected cells increased the osmotic water permeability coefficient (P f) from 2.02 ± 0.3× 10-4 to 16.37 ± 0.5× 10-4 cm/s at 20°C. Freeze-fracture EM showed distinct orthogonal arrays of particles (OAPs), the morphological signature of AQP4, on the plasma membrane of AQP4-expressing cells. Quantitative morphometry showed that the density of OAPs was 2.5 ± 0.3% under basal condition and decreased by 50% to 1.2 ± 0.3% after 20 min of histamine stimulation, mainly due to a significant decrease of the OAPs number. Concomitantly, P f decreased by ∼35% in 20-min histamine-stimulated cells. Both P f and OAPs density were not modified after 10 min of histamine exposure, time at which the maximal hormonal response is observed. Cell surface biotinylation experiments confirmed that AQP4 is internalized after 20 min of histamine exposure, which may account for the downregulation of water transport. This is the first evidence for short term rearrangement of OAPs in an established AQP4-expressing cell line.

Page Thumbnails

  • Thumbnail: Page 
1235
    1235
  • Thumbnail: Page 
1236
    1236
  • Thumbnail: Page 
1237
    1237
  • Thumbnail: Page 
1238
    1238
  • Thumbnail: Page 
1239
    1239
  • Thumbnail: Page 
1240
    1240
  • Thumbnail: Page 
1241
    1241
  • Thumbnail: Page 
1242
    1242
  • Thumbnail: Page 
1243
    1243