Dynamin is a large GTPase involved in several distinct modes of cell endocytosis. In this study, we examined the possible role of dynamin in UT-A1 internalization. The direct relationship of UT-A1 and dynamin was identified by coimmunoprecipitation. UT-A1 has cytosolic NH(2) and COOH termini and a large intracellular loop. Dynamin specifically binds to the intracellular loop of UT-A1, but not t...

The adenylyl cyclase stimulator forskolin (FSK) stimulates UT-A1 phosphorylation, membrane trafficking, and urea transport activity. Here, we found that FSK stimulation induces UT-A1 ubiquitination in UT-A1 Madin-Darby canine kidney (MDCK) cells. This suggests that phosphorylation by FSK also triggers the protein degradation machinery for UT-A1. UT-A1-MDCK cells were treated with 100 μg/ml cycl...

UT-7 is a human megakaryoblastic leukemia cell line with absolute dependence on interleukin-3, granulocyte-macrophage colony-stimulating factor, or erythropoietin (EPO) for growth and survival. We investigated the effect of thrombopoietin (TPO), the ligand for the receptor encoded by c-mpl proto-oncogene, on the proliferation and differentiation of UT-7 and its sublines. We found that UT-7/GM, ...

Urea accumulation in the renal inner medulla plays a key role in the maintenance of maximal urinary concentrating ability. Urea transport in the kidney is mediated by transporter proteins that include renal urea transporter (UT-A) and erythrocyte urea transporter (UT-B). UT-A1 and UT-A2 are produced from the same gene. There is an active tonicity-responsive enhancer (TonE) in the promoter of UT...

Urea transporter B (UT-B) is a membrane channel protein that specifically transports urea. UT-B null mouse exhibited urea selective urine concentrating ability deficiency, which suggests the potential clinical applications of the UT-B inhibitors as novel diuretics. Primary high-throughput virtual screening (HTVS) of 50000 small-molecular drug-like compounds identified 2319 hit compounds. These ...

Urea transport, mediated by the urea transporter A1 (UT-A1) and/or UT-A3, is important for the production of concentrated urine. Vasopressin rapidly increases urea transport in rat terminal inner medullary collecting ducts (IMCD). A previous study showed that one mechanism for rapid regulation of urea transport is a vasopressin-induced increase in UT-A1 phosphorylation. This study tests whether...

UT-7 is a human leukemic cell line capable of growing in interleukin-3 (IL-3). granulocyte/macrophage colony-stimulating factor (GM-CSF), or erythropoietin (Epo) (Komatsu etal, CancerRes51:341,1991).Tostudytheeffectof Epo on proliferation and differentiation of UT-7, we maintained the UT-7 cell culture for more than 6 months in the presence of Epo. As a result, a subline, UT-7/Epo, was establis...

The movement of urea across plasma membranes is modulated by facilitated urea transporter proteins. These proteins are the products of two closely related genes, termed UT-A (Slc14a2) and UT-B (Slc14a1). By genomic library screening and P1 artificial chromosome "shotgun" sequencing, we have determined the structure of the mouse UT-A gene. The gene is >300 kb in length, contains 24 exons, and ha...