Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3 Pt 1
|
pubmed:dateCreated |
1991-4-12
|
pubmed:abstractText |
Human colon adenocarcinoma (Caco-2) cells express both intrinsic factor-cobalamin receptor and transcobalamin II (TC II). The expression of these activities began to rise by day 6 and reached peak levels between 10 and 15 days in culture. The postconfluent Caco-2 cell membranes bound approximately 30-35 fmol of intrinsic factor (IF) [57Co]Cbl/mg protein. The size of the mature receptor expressed in the apical brush border had a relative molecular mass of 230 kDa. The intracellular form of TC II had a Mr of 43, 5 higher than the secreted form of TC II. TC II was secreted unidirectionally via the basolateral direction when Caco-2 cells were grown on culture inserts. When grown on culture inserts, the Caco-2 cells were polarized (electrical resistance greater than 200 omega/cm2) and transcytosed [57Co]Cbl bound to IF from apical-to-basal but not from basal-to-apical direction. Under these conditions, [57Co]Cbl complexed to haptocorrin was not transported. These cells also transcytosed free [57Co]Cbl, although less efficiently. The [57Co]Cbl transcytosed using either IF[57Co]Cbl or free [57Co]Cbl as ligands was bound exclusively to TC II. Intracellular [57Co]Cbl decreased during transcytosis with a slow (t1/2 = 4 h) transfer of [57Co]Cbl from IF to TC II. These results show that the transport of Cbl in Caco-2 cells is very similar to the human enterocyte system.
|
pubmed:grant | |
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Intrinsic Factor,
http://linkedlifedata.com/resource/pubmed/chemical/Methionine,
http://linkedlifedata.com/resource/pubmed/chemical/Sulfur Radioisotopes,
http://linkedlifedata.com/resource/pubmed/chemical/Transcobalamins,
http://linkedlifedata.com/resource/pubmed/chemical/Vitamin B 12
|
pubmed:status |
MEDLINE
|
pubmed:month |
Mar
|
pubmed:issn |
0002-9513
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
260
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
G416-22
|
pubmed:dateRevised |
2007-11-14
|
pubmed:meshHeading |
pubmed-meshheading:2003608-Adenocarcinoma,
pubmed-meshheading:2003608-Biological Transport,
pubmed-meshheading:2003608-Cell Line,
pubmed-meshheading:2003608-Colonic Neoplasms,
pubmed-meshheading:2003608-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:2003608-Humans,
pubmed-meshheading:2003608-Intrinsic Factor,
pubmed-meshheading:2003608-Kinetics,
pubmed-meshheading:2003608-Methionine,
pubmed-meshheading:2003608-Molecular Weight,
pubmed-meshheading:2003608-Sulfur Radioisotopes,
pubmed-meshheading:2003608-Transcobalamins,
pubmed-meshheading:2003608-Vitamin B 12
|
pubmed:year |
1991
|
pubmed:articleTitle |
Expression of cobalamin transport proteins and cobalamin transcytosis by colon adenocarcinoma cells.
|
pubmed:affiliation |
Department of Medicine, Medical College of Wisconsin, Milwaukee 53226.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|