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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-5-24
pubmed:abstractText
Prostasin, a novel serine protease, was purified from seminal fluid, and its cDNA sequence was determined. Expression of prostasin was detected in human tissues, including prostate, kidney, and lung, as well as bodily fluids, including seminal fluid and urine. However, its physiologic role in the human body is not known. Recently, a novel regulatory mechanism by which serine proteases activate epithelial sodium channel in the Xenopus oocyte was identified. Therefore, it was hypothesized that prostasin could activate sodium currents, and a rat prostasin cDNA clone was isolated to investigate its physiologic function. Rat prostasin mRNA is expressed predominantly in kidney, and lower levels of expression were detected in prostate, lung, colon, stomach, and skin. These all are epithelial tissues in which the epithelial sodium channel (ENaC) is expressed. Coexpression of rat prostasin and rat ENaC in Xenopus oocytes increased the amiloride-sensitive sodium current by twofold. Preincubation of oocytes that expressed prostasin with aprotinin did not result in an increase in sodium current, compared with the control. The removal of aprotinin from the bath solution resulted in a twofold increase of the current only in oocytes that expressed prostasin, which indicates that protease activity of prostasin is required for the ENaC activation. Expression of rat prostasin had no effect on the potassium current when expressed with rat renal outer medulla K channel, which shows specificity of prostasin action for ENAC: These results indicate that prostasin acts as an extracellular regulator of ENAC:
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1046-6673
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1114-21
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11373334-Amiloride, pubmed-meshheading:11373334-Animals, pubmed-meshheading:11373334-Aprotinin, pubmed-meshheading:11373334-Base Sequence, pubmed-meshheading:11373334-Blotting, Northern, pubmed-meshheading:11373334-Cloning, Molecular, pubmed-meshheading:11373334-Electrophysiology, pubmed-meshheading:11373334-Epithelium, pubmed-meshheading:11373334-Kidney Tubules, pubmed-meshheading:11373334-Oocytes, pubmed-meshheading:11373334-Patch-Clamp Techniques, pubmed-meshheading:11373334-Potassium Channels, pubmed-meshheading:11373334-Potassium Channels, Inwardly Rectifying, pubmed-meshheading:11373334-RNA, pubmed-meshheading:11373334-Rats, pubmed-meshheading:11373334-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:11373334-Serine Endopeptidases, pubmed-meshheading:11373334-Sodium Channels, pubmed-meshheading:11373334-Xenopus
pubmed:year
2001
pubmed:articleTitle
Activation of epithelial sodium channels by prostasin in Xenopus oocytes.
pubmed:affiliation
Third Department of Internal Medicine, Kumamoto University School of Medicine, Kumamoto, Japan.
pubmed:publicationType
Journal Article