Pass the bicarb: the importance of HCO3- for mucin release.
Accumulation of thick, sticky mucus is a hallmark of the genetic disease cystic fibrosis (CF) and has a central role in CF pathophysiology. Mutations in the CF transmembrane regulator (CFTR) ion channel are known to result in abnormally thick and sticky mucus; however, why mucus accumulates in CF is still not completely understood. In this issue of the JCI, Garcia and colleagues show that mucin--the heavily glycosylated protein contained within mucus--requires CFTR and bicarbonate in order to be released from mouse intestine (see the related article beginning on page 2613). The authors propose a model whereby CFTR-mediated bicarbonate secretion must be concurrent with mucin exocytosis for proper mucin release.
De Lisle
Robert C
RC
Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas 66160, USA. rdelisle@kumc.edu
D000818:Animals; D001639:Bicarbonates / Q000378:metabolism*; D003550:Cystic Fibrosis / Q000209:etiology / Q000235:genetics / Q000503:physiopathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000502:physiology; D005089:Exocytosis; D006801:Humans; D051379:Mice; D018181:Mice, Inbred CFTR; D008954:Models, Biological; D009077:Mucins / Q000378:metabolism*
D001639:Bicarbonates; C505032:CFTR protein, human; D009077:Mucins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator