Linked Life Data

8226786

Source:http://linkedlifedata.com/resource/pubmed/id/8226786

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
1993-12-1
pubmed:abstractText
CHIP28 is a major water transporting protein in erythrocytes and plasma membranes in kidney proximal tubule and thin descending limb of Henle. Chinese hamster ovary cells were stably transfected with the coding sequence of cloned rat kidney CHIP28k using expression vectors containing cytomegalovirus or Rous sarcoma virus promoters. Clonal cell populations expressed a 1.3-kilobase mRNA on Northern blot probed by CHIP28k cDNA and a 28-kDa protein on immunoblot probed by a polyclonal CHIP28 antibody. The clone with greatest expression produced approximately 8 x 10(6) copies of CHIP28k protein/cell. Plasma membrane osmotic water permeability (Pf), measured by stopped-flow light scattering, was 0.004 cm/s in control (vector-transfected) cells (10 degrees C) and 0.014 cm/s in the CHIP28k-transfected cells. Pf in CHIP28k-transfected cells had an activation energy of 4.9 kcal/mol and was reversibly inhibited by HgCl2. CHIP28k expression did not affect the transport of protons and the small polar non-electrolytes urea and formamide. CHIP28k immunoreactivity and function was then determined in subcellular fractions. Pf in 6-carboxyfluorescein-labeled endocytic vesicles, measured by a stopped-flow fluorescence quenching assay, was 0.002 cm/s (control cells) and 0.011 cm/s (CHIP28k-transfected cells); Pf in transfected cells was inhibited by HgCl2. Immunoblotting of fractionated endoplasmic reticulum, Golgi, and plasma membranes revealed high densities of CHIP28k (approximately 5000 monomers/microns 2 in plasma membrane) with different glycosylation patterns; functional water transport activity was present only in Golgi and plasma membrane vesicles. Antibody detection of CHIP28k by confocal fluorescence microscopy and immunogold electron microscopy revealed localization to plasma membrane and intracellular vesicles. These studies establish a stably transfected somatic cell line that strongly expresses functional CHIP28k water channels. As in the original proximal tubule cells, the expressed CHIP28k protein is a selective water channel that is functional in endocytic vesicles and the cell plasma membrane.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
22756-64
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8226786-Animals, pubmed-meshheading:8226786-Aquaporin 1, pubmed-meshheading:8226786-Aquaporins, pubmed-meshheading:8226786-Blotting, Northern, pubmed-meshheading:8226786-CHO Cells, pubmed-meshheading:8226786-Cattle, pubmed-meshheading:8226786-Cell Membrane, pubmed-meshheading:8226786-Cell Membrane Permeability, pubmed-meshheading:8226786-Cricetinae, pubmed-meshheading:8226786-Fluorescent Antibody Technique, pubmed-meshheading:8226786-Hydrogen-Ion Concentration, pubmed-meshheading:8226786-Immunoblotting, pubmed-meshheading:8226786-Immunohistochemistry, pubmed-meshheading:8226786-Kidney, pubmed-meshheading:8226786-Kinetics, pubmed-meshheading:8226786-Membrane Proteins, pubmed-meshheading:8226786-Microscopy, Electron, pubmed-meshheading:8226786-Rats, pubmed-meshheading:8226786-Recombinant Proteins, pubmed-meshheading:8226786-Transfection
pubmed:year
1993
pubmed:articleTitle
Localization and functional analysis of CHIP28k water channels in stably transfected Chinese hamster ovary cells.
pubmed:affiliation
Department of Medicine, University of California, San Francisco 94143-0532.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't