TY - JOUR
T1 - A ΔF508 mutation in mouse cystic fibrosis transmembrane conductance regulator results in a temperature-sensitive processing defect in vivo
AU - French, Pim J.
AU - Van Doorninck, J. Hikke
AU - Peters, Richard H.P.C.
AU - Verbeek, Elly
AU - Ameen, Nadia A.
AU - Marino, Christopher R.
AU - De Jonge, Hugo R.
AU - Bijman, Jan
AU - Scholte, Bob J.
PY - 1996/9/15
Y1 - 1996/9/15
N2 - The most prevalent mutation (ΔF508) in cystic fibrosis patients inhibits maturation and transfer to the plasma membrane of the mutant cystic fibrosis transmembrane conductance regulator (CFTR). We have analyzed the properties of a ΔF508 CFTR mouse model, which we described recently. We show that the mRNA levels of mutant CFTR are normal in all tissues examined. Therefore the reduced mRNA levels reported in two similar models may be related to their intronic transcription units. Maturation of mutant CFTR was greatly reduced in freshly excised oviduct, compared with normal. Accumulation of mutant CFTR antigen in the apical region of jejunum crypt enterocytes was not observed, in contrast to normal mice. In cultured gallbladder epithelial cells from ΔF508 mice, CFTR chloride channel activity could be detected at only two percent of the normal frequency. However, in mutant cells that were grown at reduced temperature the channel frequency increased to over sixteen percent of the normal level at that temperature. The biophysical characteristics of the mutant channel were not significantly different from normal. In homozygous ΔF508 mice we did not observe a significant effect of genetic background on the level of residual chloride channel activity, as determined by the size of the forskolin response in Ussing chamber experiments. Our data show that like its human homologue, mouse ΔF508-CFTR is a temperature sensitive processing mutant. The ΔF508 mouse is therefore a valid in vivo model of human ΔF508-CFTR. It may help us to elucidate the processing pathways of complex membrane proteins. Moreover, it may facilitate the discovery of new approaches towards therapy of cystic fibrosis.
AB - The most prevalent mutation (ΔF508) in cystic fibrosis patients inhibits maturation and transfer to the plasma membrane of the mutant cystic fibrosis transmembrane conductance regulator (CFTR). We have analyzed the properties of a ΔF508 CFTR mouse model, which we described recently. We show that the mRNA levels of mutant CFTR are normal in all tissues examined. Therefore the reduced mRNA levels reported in two similar models may be related to their intronic transcription units. Maturation of mutant CFTR was greatly reduced in freshly excised oviduct, compared with normal. Accumulation of mutant CFTR antigen in the apical region of jejunum crypt enterocytes was not observed, in contrast to normal mice. In cultured gallbladder epithelial cells from ΔF508 mice, CFTR chloride channel activity could be detected at only two percent of the normal frequency. However, in mutant cells that were grown at reduced temperature the channel frequency increased to over sixteen percent of the normal level at that temperature. The biophysical characteristics of the mutant channel were not significantly different from normal. In homozygous ΔF508 mice we did not observe a significant effect of genetic background on the level of residual chloride channel activity, as determined by the size of the forskolin response in Ussing chamber experiments. Our data show that like its human homologue, mouse ΔF508-CFTR is a temperature sensitive processing mutant. The ΔF508 mouse is therefore a valid in vivo model of human ΔF508-CFTR. It may help us to elucidate the processing pathways of complex membrane proteins. Moreover, it may facilitate the discovery of new approaches towards therapy of cystic fibrosis.
UR - http://www.scopus.com/inward/record.url?scp=0029785795&partnerID=8YFLogxK
U2 - 10.1172/JCI118917
DO - 10.1172/JCI118917
M3 - Article
C2 - 8823295
AN - SCOPUS:0029785795
SN - 0021-9738
VL - 98
SP - 1304
EP - 1312
JO - Journal of Clinical Investigation
JF - Journal of Clinical Investigation
IS - 6
ER -