Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P41181 (collecting duct)
 5,183 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Localization of protein kinase C (PKC) isoenzymes alpha, beta I, beta II, delta, and epsilon was studied employing Western blot analysis and immunohistochemical methods including confocal laser-scanning microscopy in the kidney of two mice strains, namely, C57BL/6 and 129/Sv, which have recently been used as genetic backgrounds for respective knockout mice. Immunoblot analysis identified immunoreactive bands for each isoenzyme in total kidney cell extracts. Isoenzyme expression sites were identical for both strains. Glomeruli expressed PKC-alpha, -beta I, and -epsilon. The latter isoenzyme was also detected in apical aspects of proximal convoluted but not in proximal straight tubules. In contrast to rats, neither PKC-alpha nor PKC-beta I was detectable in the proximal tubule. Immunofluorescence was observed in luminal membranes of medullary (MTAL) and cortical thick ascending limbs for PKC-beta I and in MTAL for PKC-epsilon. The cortical collecting duct expressed PKC-alpha, -beta I, and -delta in intercalated cells only. In the outer medullary collecting duct, PKC-alpha and -beta I were detectable in principal cells, whereas PKC-delta was found in intercalated cells. In the inner medullary collecting duct, PKC-alpha, -beta I, and -beta II were detected. As described for the rat, the expression of PKC-beta II was otherwise restricted to cortical and medullary interstitial cells. The specificity of all labeling was confirmed in respective PKC isoenzyme knockout mice. In summary, distinct expression patterns were shown for PKC isoenzymes alpha, beta I, beta II, delta, and epsilon in the mouse kidney.
 ...
PMID:Immunolocalization of protein kinase C isoenzymes alpha, beta I, beta II, delta, and epsilon in mouse kidney. 1503 41

In mouse kidney, the conventional protein kinase C (PKC) isoenzyme alpha is expressed in glomeruli, the cortical collecting duct (intercalated cells only), and medullary collecting duct. To get insights on its function, PKC-alpha knockout (-/-) and wild-type (+/+) mice were studied. When provided free access to water, PKC-alpha -/- mice showed approximately 50% greater urine flow rate and lower urinary osmolality in 24-h metabolic cage experiments despite a greater urinary vasopressin-to-creatinine ratio vs. PKC-alpha +/+ mice. Renal albumin excretion was not different. Clearance experiments under inactin/ketamine anesthesia revealed a modestly reduced glomerular filtration rate and showed a reduced absolute and fractional renal fluid reabsorption in PKC-alpha -/- mice. The sodium-restricting response to a low-sodium diet was unaffected in PKC-alpha -/- mice. Urinary osmolality was reduced to similar hypotonic levels in PKC-alpha -/- and +/+ mice during acute oral water loading or application of the vasopressin V(2)-receptor antagonist SR-121463. In comparison, the lower urinary osmolality observed in PKC-alpha -/- mice vs. wild-type mice under basal conditions persisted during water restriction for 36 h. In conclusion, PKC-alpha appears not to play a major role in renal sodium reabsorption but, consistent with its expression in the medullary collecting duct, contributes to urinary concentration in mice. Considering that PKC-beta I and -beta II are coexpressed with PKC-alpha in mouse medullary collecting duct, the present results indicate that conventional PKC isoenzymes cannot fully compensate for each other.
 ...
PMID:Evidence for a role of protein kinase C-alpha in urine concentration. 1503 42

We have used Western blot analysis and immunocytochemistry to determine the effect of dietary K intake on the expression of protein kinase C (PKC) isoforms in the kidney. Western blot has demonstrated that conventional PKC isoforms (alpha and beta), novel PKC isoforms (delta, epsilon, and eta), and atypical PKC isoforms (zeta) are expressed in the renal cortex and outer medulla. Moreover, a low K intake significantly increases the expression of PKC-epsilon in the renal cortex and outer medulla but does not change the expression of PKC-alpha, PKC-beta, PKC-delta, PKC-eta, and PKC-zeta. Also, immunocytochemistry shows that PKC-epsilon isoform is expressed in the cortical collecting duct (CCD) and outer medullary collecting duct (OMCD) and that the intensity of PKC-epsilon staining is higher in the kidney from rats on a K-deficient diet than those on a control diet. Also, we used the patch-clamp technique to study the role of PKC in mediating internalization of ROMK (Kir 1.1)-like small-conductance K (SK) channels induced by phenylarsine oxide (PAO), an agent that inhibits protein tyrosine phosphatase and has been shown to stimulate the internalization of the SK channel in the CCD (Sterling H, Lin DH, Qu RM, Dong K, Herbert SC, and Wang WH. J Biol Chem 277: 4317-4323, 2002). Inhibition of PKC with calphostin C and GF-109203x had no significant effect on channel activity but abolished the inhibitory effect of PAO on SK channels. In conclusion, a low K intake increases the expression of PKC-epsilon isoform in the renal cortex and outer medulla, and PKC is involved in mediating the internalization of SK channels in the CCD induced by stimulation of protein tyrosine kinase activity.
 ...
PMID:PKC expression is regulated by dietary K intake and mediates internalization of SK channels in the CCD. 1513 Aug 98

Recent studies of the distribution of PKC isoenzymes in the mouse kidney demonstrated that PKC-alpha, -beta(I), and -delta are expressed in intercalated cells. The purpose of this study was to identify the intercalated cell subtypes that express the different PKC isoenzymes and determine the location of the PKC isoenzymes within these cells. Adult C57BL/6 mice kidney tissues were processed for multiple-labeling immunohistochemistry. Antibodies against the vacuolar H(+)-ATPase and pendrin were used to identify intercalated cell subtypes, whereas antibodies against calbindin D(28K) and aquaporin-2 (AQP2) were used to identify connecting tubule cells and principal cells of the collecting duct, respectively. Within type A intercalated cells, PKC-delta was highly expressed in the apical part of the cells, whereas immunoreactivity for both PKC-alpha and PKC-beta(I) was weak. Type B intercalated cells exhibited strong expression of PKC-alpha, -beta(I), and -delta. PKC-alpha and -beta(I) were localized throughout the cytoplasm, whereas PKC-delta was restricted to the basal domain. Within non-A-non-B cells, immunoreactivity for both PKC-alpha and PKC-beta(I) was high in intensity and localized diffusely in the cytoplasm, whereas PKC-delta was localized in the apical part of the cells. None of the PKC isoenzymes (PKC-alpha, -beta(I), or -delta) were expressed in the calbindin D(28K)-positive connecting tubule cells. Within AQP2-positive principal cells of the collecting duct, PKC-alpha was expressed on the basolateral plasma membrane, but no significant staining was detected for PKC-beta(I) and -delta. In summary, this study demonstrates distinct and differential expression patterns of PKC-alpha, -beta(I), and -delta in the three subtypes of intercalated cells in the mouse kidney.
 ...
PMID:Expression of protein kinase C isoenzymes alpha, betaI, and delta in subtypes of intercalated cells of mouse kidney. 1673 62