spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online March 17, 2006
Journal of Experimental Biology 209, 1207-1216 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02123
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Konno, N.
Right arrow Articles by Uchiyama, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Konno, N.
Right arrow Articles by Uchiyama, M.

Effect of osmotic stress on expression of a putative facilitative urea transporter in the kidney and urinary bladder of the marine toad, Bufo marinus

Norifumi Konno1, Susumu Hyodo2, Kouhei Matsuda1 and Minoru Uchiyama1,*

1 Department of Biology, Faculty of Science, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan
2 Laboratory of Physiology, Ocean Research Institute, University of Tokyo, 1-15-1 Minamidai, Nakano, Tokyo, 164-8639, Japan


Figure 1
View larger version (65K):

[in a new window]
  		Fig. 1. Primary structure of the urea transporter (UT) isolated from the kidney of Bufo marinus. (A) The deduced amino acid sequence is aligned with those of Rana esculenta UT (GenBank accession no. Y12784), rat UT-A2 (U09957) and rat UT-B2 (U81518) using the Clustal algorithm. Asterisks denote identical amino acid residues; the horizontal bars indicate the predicted transmembrane regions; the box indicates putative N-glycosylation sites; the underline indicates the ALE domain, which is considered to be a signature sequence for UT-B. (B) Kyte-Doolittle hydropathy profile of the deduced Bufo UT amino acid sequence predicts the presence of trans-membrane regions (1–10).

 

Figure 2
View larger version (23K):

[in a new window]
  		Fig. 2. RT–PCR analysis of tissue distribution of Bufo urea transporter (UT) mRNA. PCR was performed using specific primers for Bufo UT and frog GAPDH. ++, Strong expression; +, weak expression; –, absence of the mRNA.

 

Figure 3
View larger version (22K):

[in a new window]
  		Fig. 3. Expression of Bufo urea transporter (UT) mRNA relative to GAPDH mRNA in the kidney (A) and urinary bladder (B) of marine toads exposed to dry or hyper-saline conditions. The signal level of each band in Ai, Bi is presented as a ratio of Bufo UT/GAPDH mRNA in Aii, Bii, respectively. Values are means ± s.e.m. N=5. Bars with different letters have significantly different values (ANOVA, P<0.05).

 

Figure 4
View larger version (61K):

[in a new window]
  		Fig. 4. Immunoblot analysis of urea transporter (UT) protein expressed in the kidney and urinary bladder of the marine toad. The affinity-purified Bufo UT antibody recognized a single band of 52 kDa in extracts of the kidney (lane 1) and urinary bladder (lane 2), but not of heart (lane 3) and liver (lane 4) on negative control tissues. These bands disappeared after preabsorption with the synthetic immunogen (kidney, lane 5; urinary bladder, lane 6).

 

Figure 5
View larger version (102K):

[in a new window]
  		Fig. 5. Immunohistochemical localization of the urea transporter (UT; stained brown) in the kidney of Bufo using affinity-purified Bufo UT antibody. (A) Immunoreactivity was detected on the apical cell membrane of epithelia in the early distal tubules, located in the ventral zone (boxed) of the kidney. (B) Higher magnification of the immunoreactive apical cell membrane in the early distal tubules. (C,D) In adjacent sections, no UT immunoreactivity was detected in the late distal tubule and collecting duct where H+-ATPase was expressed. (E,F) Diagrams showing the distribution of UT and H+-ATPase in the renal nephron, indicated by red asterisk in each scheme, respectively. Arrowheads in C and D, early distal tubule (ED); arrows in C and D, late distal tubule (LD). Ad, adrenal gland; G, glomerulus; P, proximal tubule. Scale bars, (A,C,D) 100 µm; (B) 20 µm.

 




© The Company of Biologists Ltd 2006