ISSN:
1437-7799
Schlagwort(e):
Key words pICln
;
Chloride channel
;
LLC-PK1
;
ATP
;
Azide
;
Dihydrocytochalasin
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Abstract Background. There has been no conclusive explanation regarding the function of pICln (a 26- to 27-kDa acidic protein) on an osmo-sensitive chloride channel responsible for an outwardly rectifying anion current. We observed the effects of the hypotonic treatment of LLC-PK1 cells on the intra-cellular dynamic state of pICln. Methods. LLC-PK1 cells were cultured, and pICln in cells was observed immunohistochemically. The cells were fractionated into nuclei, mitochondrial, microsomal, and soluble fractions biochemically, and pICln was detected by an immunoblotting method after sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Results. pICln in cells was observed on nuclei and their surroundings, but not on cell membranes. pICln was present in soluble and insoluble forms. The molecular masses of the oligomeric forms in the soluble fractions were different from those previously reported with Madin-Darby canine kidney (MDCK) cells, indicating the differences in the pICln-oligomer depending on cell type. On analysis with SDS-polyacrylamide gel electrophoresis, the exposure of cells to hypotonic media elevated the ratio of soluble to insoluble forms within 5 min. This result also conflicted with those previously reported with MDCK cells. This finding suggests that the function of pICln and the signaling mechanism differ depending on the cell species. Both extracellular ATP and NaN3 inhibited this elevation of the soluble/insoluble ratio, coinciding with previous reports that extracellular nucleotides and depletion of intracellular ATP inhibited the volume-sensitive chloride channel. Dihydrocytochalasin B, an F-actin-disrupting drug, inhibited the elevation of the soluble/insoluble ratio. Conclusions. The soluble form of pICln was increased within 5 min by exposure of LLC-PK1 cells to hypotonic media. This translocation was inhibited by extracellular ATP, NaN3, and dihydrocytochalasin.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s101570050029
Permalink
