CFTR protein expression in primary and cultured epithelia.
The gene responsible for the lethal disorder cystic fibrosis encodes a 1480-amino acid glycoprotein, CFTR. Using polyclonal antibodies directed against separate phosphorylation sites in the pre-nucleotide-binding fold (exon 9) and the R domain (exon 13), we have identified a 165-kDa protein in Xenopus laevis oocytes injected with recombinant CFTR cRNA transcribed from the full-length CFTR plasmid pBQ4.7. A protein of the same mobility was also detected with Western blotting techniques in whole cell extracts of cells that express CFTR mRNA (T84, FHTE, HT-29), including biopsied human nasal and bronchial tissue. Immunodetectable 165-kDa protein was concentrated in the apical membrane fraction of ileal villus tissue. We also report that the 165-kDa protein levels can be modulated pharmacologically, and these levels are appropriately correlated with second-messenger-regulated Cl- efflux. Thus, native or recombinant CFTR can be recognized by these anti-CFTR peptide polyclonal antibodies.
Zeitlin
P L
PL
Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Crawford
I
I
Lu
L
L
Woel
S
S
Cohen
M E
ME
Donowitz
M
M
Montrose
M H
MH
Hamosh
A
A
Cutting
G R
GR
Gruenert
D
D
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D002478:Cells, Cultured; D018118:Chloride Channels; D003550:Cystic Fibrosis / Q000378:metabolism*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D004848:Epithelium / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism*; D009865:Oocytes; D010455:Peptides / Q000276:immunology; D011817:Rabbits; D014982:Xenopus laevis
C505032:CFTR protein, human; D018118:Chloride Channels; D008565:Membrane Proteins; D010455:Peptides; D019005:Cystic Fibrosis Transmembrane Conductance Regulator