Mucin granule-associated proteins in human bronchial epithelial cells: the airway goblet cell "granulome" Public Deposited

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Creator
  • Crews, Anne L
    • Other Affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
  • Fang, Shijing
    • Other Affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
  • Park, Joungjoa
    • Other Affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
  • Adler, Kenneth B
    • Other Affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
  • Raiford, Kimberly L
    • Affiliation: School of Medicine, Department of Biochemistry and Biophysics
  • Lin, Ko-Wei
    • Other Affiliation: Department of Medicine, University of California, San Diego, California, USA
Abstract
  • Abstract Background Excess mucus in the airways leads to obstruction in diseases such as chronic bronchitis, asthma, and cystic fibrosis. Mucins, the highly glycosolated protein components of mucus, are stored in membrane-bound granules housed in the cytoplasm of airway epithelial "goblet" cells until they are secreted into the airway lumen via an exocytotic process. Precise mechanism(s) of mucin secretion, including the specific proteins involved in the process, have yet to be elucidated. Previously, we have shown that the Myristoylated Alanine-Rich C Kinase Substrate (MARCKS) protein regulates mucin secretion by orchestrating translocation of mucin granules from the cytosol to the plasma membrane, where the granules dock, fuse and release their contents into the airway lumen. Associated with MARCKS in this process are chaperone (Heat Shock Protein 70 [HSP70], Cysteine string protein [CSP]) and cytoskeletal (actin, myosin) proteins. However, additional granule-associated proteins that may be involved in secretion have not yet been elucidated. Methods Here, we isolated mucin granules and granule membranes from primary cultures of well differentiated human bronchial epithelial cells utilizing a novel technique of immuno-isolation, based on the presence of the calcium activated chloride channel hCLCA1 (the human ortholog of murine Gob-5) on the granule membranes, and verified via Western blotting and co-immunoprecipitation that MARCKS, HSP70, CSP and hCLCA1 were present on the granule membranes and associated with each other. We then subjected the isolated granules/membranes to liquid chromatography mass spectrometry (LC-MS/MS) to identify other granule associated proteins. Results A number of additional cytoskeletal (e.g. Myosin Vc) and regulatory proteins (e.g. Protein phosphatase 4) associated with the granules and could play a role in secretion were discovered. This is the first description of the airway goblet cell "granulome."
Date of publication
Identifier
  • doi:10.1186/1465-9921-12-118
  • 21896166
Resource type
  • Article
Rights statement
  • In Copyright
Rights holder
  • Kimberly L Raiford et al.; licensee BioMed Central Ltd.
License
Journal title
  • Respiratory Research
Journal volume
  • 12
Journal issue
  • 1
Page start
  • 118
Language
  • English
Is the article or chapter peer-reviewed?
  • Yes
ISSN
  • 1465-9921
Bibliographic citation
  • Respiratory Research. 2011 Sep 06;12(1):118
Access
  • Open Access
Publisher
  • BioMed Central Ltd
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