title: Mammalian short palate lung and nasal epithelial clone 1 (SPLUNC1) in pH-dependent airway hydration.
abstract: The epithelia that line the conducting airways are the lung's first point of contact with inhaled pathogens and toxicants. As such, they are known to play an important role in the lung's innate defense system, which includes (i) the production of airway surface liquid (ASL) that helps cleanse the airways through the physical removal of pathogens and toxicants on the mucociliary escalator and (ii) the secretion of anti-microbial proteins into the ASL to kill inhaled pathogens. Interestingly, the recently crystallized short palate lung and nasal epithelial clone 1 (SPLUNC1) protein appears to be a multi-functional protein. That is, it not only acts as an anti-microbial agent, but also modulates ASL homeostasis by acting as an endogenous inhibitor of the epithelial Na(+) channel (ENaC). This review will focus on the latter function of SPLUNC1, and will discuss new structural and physiological data regarding SPLUNC1's failure to function as a regulator of ASL hydration in CF airways.
authors.affiliation: Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA. Electronic address: robert_tarran@med.unc.edu.
authors.forename: Robert
authors.initials: R
authors.lastname: Tarran
authors.affiliation: Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA. Electronic address: redinbo@unc.edu.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Redinbo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003550:Cystic Fibrosis / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008168:Lung / Q000378:metabolism*; D008969:Molecular Sequence Data; D009296:Nasal Cavity / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000378:metabolism*
chemical_list: C485599:BPIFA1 protein, human; D006023:Glycoproteins; D010750:Phosphoproteins
keywords: Airway epithelia; BPIFA1; Cystic fibrosis; ENaC; PLUNC