Distribution and diversity of Na-K-Cl cotransport proteins: a study with monoclonal antibodies

1995 ◽  
Vol 269 (6) ◽  
pp. C1496-C1505 ◽  
Author(s):  
C. Lytle ◽  
J. C. Xu ◽  
D. Biemesderfer ◽  
B. Forbush
Keyword(s):  
Monoclonal Antibodies ◽  
Loop Diuretic ◽  
Chloride Secretion ◽  
Salt Transport ◽  
Rabbit Kidney ◽  
Thick Ascending Limb ◽  
Animal Cells ◽  
Immunoreactive Protein ◽  
Site Density ◽  
Carboxy Terminal

The Na-K-Cl cotransporter (NKCC) is present in most animal cells where it functions in cell volume homeostasis and epithelial salt transport. We developed six monoclonal antibodies (designated T4, T8, T9, T10, T12, and T14) against a fusion protein fragment encompassing the carboxy-terminal 310 amino acids of the human colonic NKCC. These T antibodies selectively recognized putative NKCC proteins in a diverse variety of animal tissues. Western blot analysis of membranes isolated from 23 types of cells identified single bands of immunoreactive protein ranging in mass from 146 to 205 kDa. The amount of immunoreactive protein detected in these cells correlated with loop diuretic binding site density. Proteins identified previously as Na-K-Cl cotransporters by loop diuretic photoaffinity labeling were mutually recognized by multiple T antibodies. Most of the T antibodies effectively immunoprecipitated the denatured form of the NKCC protein. Immunocytochemical studies on the rabbit parotid gland demonstrated that NKCC is restricted to the basolateral margin of the acinar cells and absent from the ducts, in accord with the central role of Na-K-Cl cotransport in chloride secretion. In the rabbit kidney, NKCC was localized to the apical membrane of thick ascending limb cells, consistent with its role in chloride reabsorption.

scholarly journals The Catenin p120ctnInteracts with Kaiso, a Novel BTB/POZ Domain Zinc Finger Transcription Factor

1999 ◽  
Vol 19 (5) ◽  
pp. 3614-3623 ◽  
Author(s):  
Juliet M. Daniel ◽  
Albert B. Reynolds
Keyword(s):  
Transcription Factor ◽  
Monoclonal Antibodies ◽  
Cell Adhesion ◽  
Mammalian Cells ◽  
Yeast Two Hybrid ◽  
Amino Terminal ◽  
Juxtamembrane Region ◽  
Carboxy Terminal ◽  
Two Hybrid ◽  
E Cadherin

ABSTRACT p120 ctn is an Armadillo repeat domain protein with structural similarity to the cell adhesion cofactors β-catenin and plakoglobin. All three proteins interact directly with the cytoplasmic domain of the transmembrane cell adhesion molecule E-cadherin; β-catenin and plakoglobin bind a carboxy-terminal region in a mutually exclusive manner, while p120 binds the juxtamembrane region. Unlike β-catenin and plakoglobin, p120 does not interact with α-catenin, the tumor suppressor adenomatous polyposis coli (APC), or the transcription factor Lef-1, suggesting that it has unique binding partners and plays a distinct role in the cadherin-catenin complex. Using p120 as bait, we conducted a yeast two-hybrid screen and identified a novel transcription factor which we named Kaiso. Kaiso’s deduced amino acid sequence revealed an amino-terminal BTB/POZ protein-protein interaction domain and three carboxy-terminal zinc fingers of the C2H2 DNA-binding type. Kaiso thus belongs to a rapidly growing family of POZ-ZF transcription factors that include the Drosophila developmental regulators Tramtrak and Bric à brac, and the human oncoproteins BCL-6 and PLZF, which are causally linked to non-Hodgkins’ lymphoma and acute promyelocytic leukemia, respectively. Monoclonal antibodies to Kaiso were generated and used to immunolocalize the protein and confirm the specificity of the p120-Kaiso interaction in mammalian cells. Kaiso specifically coprecipitated with a variety of p120-specific monoclonal antibodies but not with antibodies to α- or β-catenin, E-cadherin, or APC. Like other POZ-ZF proteins, Kaiso localized to the nucleus and was associated with specific nuclear dots. Yeast two-hybrid interaction assays mapped the binding domains to Arm repeats 1 to 7 of p120 and the carboxy-terminal 200 amino acids of Kaiso. In addition, Kaiso homodimerized via its POZ domain but it did not heterodimerize with BCL-6, which heterodimerizes with PLZF. The involvement of POZ-ZF proteins in development and cancer makes Kaiso an interesting candidate for a downstream effector of cadherin and/or p120 signaling.

Carbonic anhydrase XII mRNA encodes a hydratase that is differentially expressed along the rabbit nephron

2003 ◽  
Vol 284 (2) ◽  
pp. F399-F410 ◽  
Author(s):  
George J. Schwartz ◽  
Anne M. Kittelberger ◽  
Richard H. Watkins ◽  
Michael A. O'Reilly
Keyword(s):  
Carbonic Anhydrase ◽  
Transmembrane Protein ◽  
Proximal Tubules ◽  
Rabbit Kidney ◽  
Kidney Cortex ◽  
Thick Ascending Limb ◽  
Basolateral Membranes ◽  
Collecting Ducts ◽  
Straight Tubules ◽  
Hydratase Activity

Membrane-bound carbonic anhydrase (CA) facilitates acidification in the kidney. Although most hydratase activity is considered due to CA IV, some in the basolateral membranes could be attributed to CA XII. Indeed, CA IV is glycosylphosphatidylinositol anchored, connoting apical polarization, but CA IV immunoreactivity has been detected on basolateral membranes of proximal tubules. Herein, we determined whether CA XII mRNA was expressed in acidifying segments of the rabbit nephron. The open reading frame of CA XII was sequenced from a rabbit kidney cortex cDNA library; it was 83% identical to human CA XII and coded for a 355-amino acid single-pass transmembrane protein. Northern blot analysis revealed an abundant 4.5-kb message in kidney cortex, medulla, and colon. By in situ hybridization, CA XII mRNA was expressed by proximal convoluted and straight tubules, cortical and medullary collecting ducts, and papillary epithelium. By RT-PCR, CA XII mRNA was abundantly expressed in cortical and medullary collecting ducts and thick ascending limb of Henle's loop; it was also expressed in proximal convoluted and straight tubules but not in glomeruli or S3 segments. FLAG-CA XII of ∼40 kDa expressed in Escherichia coli showed hydratase activity that was inhibited by 0.1 mM acetazolamide. Unlike CA IV, expressed CA XII activity was inhibited by 1% SDS, suggesting insufficient disulfide linkages to stabilize the molecule. Western blotting of expressed CA XII with two anti-rabbit CA IV peptide antibodies showed no cross-reactivity. Our findings indicate that CA XII may contribute to the membrane CA activity of proximal tubules and collecting ducts.

Bumetanide: A New Loop Diuretic (Bumex, Roche Laboratories)

1983 ◽  
Vol 17 (11) ◽  
pp. 786-797 ◽  
Author(s):  
Charles E. Halstenson ◽  
Gary R. Matzke
Keyword(s):  
Loop Diuretic ◽  
Hepatic Cirrhosis ◽  
Fluid Retention ◽  
Pharmacokinetic Parameters ◽  
Clinical Settings ◽  
Thick Ascending Limb ◽  
Loop Of Henle ◽  
Serum Concentrations ◽  
Increased Risk ◽  
Reaction Profile

Bumetanide is a recently introduced diuretic that inhibits sodium transport in the thick ascending limb of the loop of Henle. It is structurally and pharmacologically similar to furosemide, but is approximately 40 times as potent on a milligram-for-milligram basis. After oral administration, it is rapidly absorbed, with peak serum concentrations attained at approximately 30 minutes. Its pharmacokinetic parameters are similar to those of furosemide. Bumetanide has demonstrated efficacy in the management of edema associated with congestive heart failure, hepatic cirrhosis, and renal insufficiency. Bumetanide has demonstrated an adverse-reaction profile similar to that of furosemide, although the incidence of hypochloremia and hypokalemia is greater with bumetanide. The incidence of hyperglycemia and ototoxicity is greater with furosemide. The principal indication for bumetanide may be in patients with increased risk of ototoxicity. Cost considerations should relegate bumetanide to a secondary role for the treatment of sodium and fluid retention in most clinical settings.

A second rubella vaccine

1971 ◽  
Vol 9 (13) ◽  
pp. 52-52
Keyword(s):  
Tissue Culture ◽  
Pregnant Women ◽  
Rabbit Kidney ◽  
Kidney Cells ◽  
Animal Cells ◽  
Rubella Vaccine ◽  
Human Diploid Cells ◽  
Diploid Cells

Available vaccines used in protection against rubella employ strains of virus attenuated by passage in animal cells. The first vaccine that was introduced in Britain, the Cendehill vaccine (Cendevax),1 is grown on tissue culture of rabbit kidney cells. Recently another rubella vaccine (Almevax live attenuated, Wistar RA 27/3), grown on human diploid cells, has been introduced. This vaccine induces antibodies as effectively as earlier vaccines, and the indications for its use are similar to those for the Cendehill vaccine.1 2 It is very important that pregnant women, women who might be pregnant, or women likely to become pregnant within 2 months, must not be vaccinated.

Hormonal regulation of calcium transport in thick ascending limb renal tubules

1981 ◽  
Vol 241 (2) ◽  
pp. F171-F174 ◽  
Author(s):  
W. N. Suki ◽  
D. Rouse
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Hormonal Regulation ◽  
Calcium Transport ◽  
Rabbit Kidney ◽  
Renal Tubules ◽  
Similar Response ◽  
Thick Ascending Limb ◽  
Calcium Efflux ◽  
Bathing Medium

Net calcium efflux (JCanet) was compared in isolated perfused cortical and medullary segments of the thick ascending limb of Henle of the rabbit kidney. In response to the addition of calcitonin to the bathing medium, cortical segments showed no change in JCanet, whereas in medullary segments JCanet increased significantly. Similar studies substituting 8-bromo-cyclic AMP (8-BrcAMP) in concentrations of 10(-4) M or lower in the bath showed no effect on JCanet in either segment. When the concentration of 8-BrcAMP in the bath was increased to 10(-3) M, JCanet rose significantly in both segments. These results indicate heterogeneity of response to calcitonin in the cortical and medullary segments of the thick ascending limb of Henle, but a similar response of calcium transport to cAMP. Because we have previously shown that parathyroid hormone stimulates net calcium efflux in the cortical but not in the medullary segments of the thick ascending limb of Henle, the present observations suggest that cAMP may be the mediator of the actions of both calcitonin and parathyroid hormone.

scholarly journals The Babesia bovis Merozoite Surface Antigen 1 Hypervariable Region Induces Surface-Reactive Antibodies That Block Merozoite Invasion

2006 ◽  
Vol 74 (6) ◽  
pp. 3663-3667 ◽  
Author(s):  
Tanya LeRoith ◽  
Shawn J. Berens ◽  
Kelly A. Brayton ◽  
Stephen A. Hines ◽  
Wendy C. Brown ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Surface Antigen ◽  
Hypervariable Region ◽  
Babesia Bovis ◽  
Related Family ◽  
Erythrocyte Invasion ◽  
Merozoite Surface Antigen ◽  
Carboxy Terminal ◽  
Blocking Antibodies

ABSTRACT A hypervariable region (HVR) previously identified in the carboxy-terminal one-third of the Babesia bovis variable merozoite surface antigen family was more extensively analyzed in merozoite surface antigen 1 (MSA-1) from 16 strains and isolates. The MSA-1 HVR is proline rich and contains three semiconserved motifs nearly identical to those described for the related family member MSA-2. Two MSA-1-specific monoclonal antibodies previously shown to be reactive with the merozoite surface bound to a recombinant construct encoding the HVR, indicating that the HVR is surface exposed and accessible to antibody binding. Importantly, these surface-reactive, HVR-specific monoclonal antibodies were capable of inhibiting merozoite infectivity of the host erythrocyte in vivo. The results indicate that the MSA-1 HVR is involved in erythrocyte invasion and suggest that selection of MSA-1 variants may be driven by invasion-blocking antibodies.

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