Proceedings of the American Thoracic Society Email Content Delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

The Proceedings of the American Thoracic Society 3:493 (2006)
© 2006 The American Thoracic Society
doi: 10.1513/pats.200603-067MS
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Park, J.
Right arrow Articles by Adler, K. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Park, J.
Right arrow Articles by Adler, K. B.

Regulation of Airway Mucin Secretion by MARCKS Protein Involves the Chaperones Heat Shock Protein 70 and Cysteine String Protein

Joungjoa Park, Shijing Fang and Kenneth B. Adler

Department of Molecular and Biomedical Science, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina

Correspondence and requests for reprints should be addressed to Kenneth B. Adler, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street at Wm. Moore Drive, Raleigh, NC 27606. E-mail: kenneth_adler{at}ncsu.edu

We have reported previously that MARCKS protein is a key regulatory molecule controlling mucin secretion by airway epithelial cells in vitro and in vivo, and presented evidence supporting a mechanism whereby MARCKS regulates secretion by translocating from plasma membrane to cytoplasm, where it binds to membranes of intracellular mucin granules (1, 2). The actual mechanism whereby MARCKS is targeted to and attaches onto membranes of mucin granules has not been elucidated. We hypothesized that two specific chaperone proteins, cysteine string protein (CSP) and heat shock protein 70 (Hsp/Hsc70), play important roles in this process, and do so by complexing with MARCKS on the mucin granule membrane. Both Hsp/Hsc70 and CSP were found to be present in normal human bronchial epithelial (NHBE) cells. CSP was localized to membranes of intracellular mucin granules, as determined by ultrastructural immunohistochemistry and Western blotting of isolated mucin granule membranes. Coimmunoprecipitation and Western blotting showed that CSP within these cells complexed with both MARCKS and Hsp/Hsc70. A peptide against the C-terminus of CSP added to NHBE cells attenuated mucin secretion in a concentration-dependent manner, whereas a control missense peptide had no effect. This C-terminal peptide also blocked binding of MARCKS to mucin granule membranes. Transfection of HBE1 cells, a virally transformed human airway epithelial cell line, with siRNA constructs against MARCKS, CSP, or Hsp70 attenuated mucin secretion, indicating that these proteins are involved in the process. The results suggest that CSP, and specifically its C-terminus, associates with membranes of mucin granules in airway secretory cells and, apparently in conjunction with Hsp/Hsc70, plays a role in MARCKS attachment to granule membranes during the secretory process.

FOOTNOTES

Supported by grant R37 HL36982 from the National Institutes of Health (K.B.A.).

Conflict of Interest Statement: J.P. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript. S.F. does not have a financial relationship with a commercial entity that has an interest in the subject of this manuscript. K.B.A. serves on the scientific advisory board of Sepracor, Inc., and received $5,000 for this service in 2005. He served as a consultant to Immunogen and received $1,500 in 2004. He received $68,000 in 2004–2005 as a research grant from AstraZeneca and approximately $40,000 in research grants from Sepracor since 2002. He holds 150,000 founders' shares of a start-up biotech company, BioMarck, and serves as a scientific consultant and member of the scientific advisory board without monetary compensation.

(Received in original form March 17, 2006; accepted in final form March 28, 2006)

REFERENCES

  1. Li Y, Martin LD, Spizz G, Adler KB. MARCKS protein is a key molecule regulating mucin secretion by human airway epithelial cells in vitro. J Biol Chem 2001;276:40982–40990.[Abstract/Free Full Text]
  2. Singer M, Martin LD, Vargaftig BB, Park J, Gruber AD, Li Y, Adler KB. A MARCKS-related peptide blocks mucus hypersecretion in a mouse model of asthma. Nat Med 2004;10:193–196.[CrossRef][Medline]




This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Park, J.
Right arrow Articles by Adler, K. B.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Park, J.
Right arrow Articles by Adler, K. B.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS