The University of Southampton
University of Southampton Institutional Repository

Relocalization of the V-ATPase B2 subunit to the apical membrane of epididymal clear cells of mice deficient in the B1 subunit

Relocalization of the V-ATPase B2 subunit to the apical membrane of epididymal clear cells of mice deficient in the B1 subunit
Relocalization of the V-ATPase B2 subunit to the apical membrane of epididymal clear cells of mice deficient in the B1 subunit
An acidic luminal pH in the epididymis contributes to maintaining sperm quiescent during their maturation and storage. The vacuolar H(+)ATPase (V-ATPase), located in narrow and clear cells, is a major contributor to luminal acidification. Mutations in one of the V-ATPase subunits, ATP6v1B1 (B1), cause distal renal tubular acidosis in humans but surprisingly, B1(-/-) mice do not develop metabolic acidosis and are fertile. While B1 is located in the apical membrane of narrow and clear cells, the B2 subunit localizes to subapical vesicles in wild-type mouse, rat and human epididymis. However, a marked increase (84%) in the mean pixel intensity of B2 staining was observed in the apical pole of clear cells by conventional immunofluorescence, and relocalization into their apical membrane was detected by confocal microscopy in B1(-/-) mice compared with B1(+/+). Immunogold electron microscopy showed abundant B2 in the apical microvilli of clear cells in B1(-/-) mice. B2 mRNA expression, determined by real time RT-PCR using laser-microdissected epithelial cells, was identical in both groups. Semiquantitative Western blots from whole epididymis and cauda epididymidis showed no variation of B2 expression. Finally, the luminal pH of the cauda epididymidis was the same in B1(-/-) mice as in B1(+/+) (pH 6.7). These data indicate that whereas overall expression of B2 is not affected in B1(-/-) mice, significant redistribution of B2-containing complexes occurs from intracellular compartments into the apical membrane of clear cells in B1(-/-) mice. This relocation compensates for the absence of functional B1 and maintains the luminal pH in an acidic range that is compatible with fertility
0363-6143
C199-210
Da Silva, Nicolas
1e819b5f-b4cf-4606-a919-c8bec5742c24
Shum, Winnie W.C.
281a8f93-c5cc-4e9d-9eda-f3c659e695f9
El-Annan, Jaafar
f4e1cb23-9505-4e7f-bdfd-b6839b32f2e1
Păunescu, Teodor G.
18f45973-8745-4c62-9a77-b762f6097023
McKee, Mary
43845e94-863a-4206-b835-b59ecea9a9d4
Smith, Peter J.S.
003de469-9420-4f12-8f0e-8e8d76d28d6c
Brown, Dennis
6938f113-e019-4a94-b66a-ae244ae2e6d7
Breton, Sylvie
2e794185-ff02-4aef-a2b3-a390eb5552b5
Da Silva, Nicolas
1e819b5f-b4cf-4606-a919-c8bec5742c24
Shum, Winnie W.C.
281a8f93-c5cc-4e9d-9eda-f3c659e695f9
El-Annan, Jaafar
f4e1cb23-9505-4e7f-bdfd-b6839b32f2e1
Păunescu, Teodor G.
18f45973-8745-4c62-9a77-b762f6097023
McKee, Mary
43845e94-863a-4206-b835-b59ecea9a9d4
Smith, Peter J.S.
003de469-9420-4f12-8f0e-8e8d76d28d6c
Brown, Dennis
6938f113-e019-4a94-b66a-ae244ae2e6d7
Breton, Sylvie
2e794185-ff02-4aef-a2b3-a390eb5552b5

Da Silva, Nicolas, Shum, Winnie W.C., El-Annan, Jaafar, Păunescu, Teodor G., McKee, Mary, Smith, Peter J.S., Brown, Dennis and Breton, Sylvie (2007) Relocalization of the V-ATPase B2 subunit to the apical membrane of epididymal clear cells of mice deficient in the B1 subunit. American Journal of Physiology: Cell Physiology, 293 (1), C199-210. (doi:10.1152/ajpcell.00596.2006). (PMID:17392376)

Record type: Article

Abstract

An acidic luminal pH in the epididymis contributes to maintaining sperm quiescent during their maturation and storage. The vacuolar H(+)ATPase (V-ATPase), located in narrow and clear cells, is a major contributor to luminal acidification. Mutations in one of the V-ATPase subunits, ATP6v1B1 (B1), cause distal renal tubular acidosis in humans but surprisingly, B1(-/-) mice do not develop metabolic acidosis and are fertile. While B1 is located in the apical membrane of narrow and clear cells, the B2 subunit localizes to subapical vesicles in wild-type mouse, rat and human epididymis. However, a marked increase (84%) in the mean pixel intensity of B2 staining was observed in the apical pole of clear cells by conventional immunofluorescence, and relocalization into their apical membrane was detected by confocal microscopy in B1(-/-) mice compared with B1(+/+). Immunogold electron microscopy showed abundant B2 in the apical microvilli of clear cells in B1(-/-) mice. B2 mRNA expression, determined by real time RT-PCR using laser-microdissected epithelial cells, was identical in both groups. Semiquantitative Western blots from whole epididymis and cauda epididymidis showed no variation of B2 expression. Finally, the luminal pH of the cauda epididymidis was the same in B1(-/-) mice as in B1(+/+) (pH 6.7). These data indicate that whereas overall expression of B2 is not affected in B1(-/-) mice, significant redistribution of B2-containing complexes occurs from intracellular compartments into the apical membrane of clear cells in B1(-/-) mice. This relocation compensates for the absence of functional B1 and maintains the luminal pH in an acidic range that is compatible with fertility

Text
C199.full.pdf - Version of Record
Restricted to Repository staff only
Request a copy

More information

Published date: July 2007
Organisations: University of Southampton

Identifiers

Local EPrints ID: 190279
URI: http://eprints.soton.ac.uk/id/eprint/190279
ISSN: 0363-6143
PURE UUID: cb973730-4887-479a-81cc-6c0d9a051baf
ORCID for Peter J.S. Smith: ORCID iD orcid.org/0000-0003-4400-6853

Catalogue record

Date deposited: 13 Jun 2011 12:24
Last modified: 19 Nov 2019 01:39

Export record

Altmetrics

Contributors

Author: Nicolas Da Silva
Author: Winnie W.C. Shum
Author: Jaafar El-Annan
Author: Teodor G. Păunescu
Author: Mary McKee
Author: Dennis Brown
Author: Sylvie Breton

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×