Differential protein abundance and function of UT-B urea transporters in human colon.

Abstract

Facilitative UT-B urea transporters enable the passage of urea across cell membranes. Gastrointestinal urea transporters are thought to play a significant role in the urea nitrogen salvaging process that occurs between mammalian hosts and their gut bacteria. This study investigated the expression of UT-B urea transporters in different segments of human colon. Immunoblot analysis showed that human colon expressed a 35-kDa glycosylated UT-B protein in the colonic mucosa. The 35-kDa UT-B transporter was predominantly located in plasma membrane-enriched samples (P < 0.001; n = 6), and its expression was greater in the ascending colon compared with the descending colon (P < 0.01; n = 3). At the cellular level, UT-B transporters were located throughout colonocytes situated in the upper portion of the colonic crypts. Bidirectional trans-epithelial urea transport was significantly greater in the ascending colon than the descending colon (P < 0.05; n = 6). In addition, the facilitative urea transporter inhibitor 1,3,dimethylurea significantly reduced urea transport in the ascending colon (P < 0.05; n = 6) but had no effect in the descending colon (NS; n = 6). These results illustrate differential protein abundance of functional UT-B protein in different sections of the human colon, strongly correlating to regions that contain the largest populations of intestinal bacteria. This study suggests an important role for UT-B urea transporters in maintaining the symbiotic relationship between humans and their gut bacteria.

DOI: 10.1152/ajpgi.00405.2009

8 Figures and Tables

010020020102011201220132014201520162017
Citations per Year

369 Citations

Semantic Scholar estimates that this publication has 369 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Collins2010DifferentialPA, title={Differential protein abundance and function of UT-B urea transporters in human colon.}, author={Danielle Collins and Desmond C. Winter and Aisling Maria Hogan and Lucas Schirmer and Alan William Baird and Greg Stewart}, journal={American journal of physiology. Gastrointestinal and liver physiology}, year={2010}, volume={298 3}, pages={G345-51} }