Source:http://linkedlifedata.com/resource/pubmed/id/16377632
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
8
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| pubmed:dateCreated |
2006-2-20
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| pubmed:abstractText |
Recent studies suggest that the mucin granule lumen consists of a matrix meshwork embedded in a fluid phase. Secretory products can both diffuse, although very slowly, through the meshwork pores and interact noncovalently with the matrix. Using a green fluorescent protein-mucin fusion protein (SHGFP-MUC5AC/CK) as a FRAP (fluorescence recovery after photobleaching) probe, we have assessed in living mucous cells the relative importance of different protein post-translational modifications on the intragranular organization. Long term inhibition of mucin-type O-glycosylation, sialylation, or sulfation altered SHGFP-MUC5AC/CK characteristic diffusion time (t(1/2)), whereas all but sulfation diminished its mobile fraction. Reduction of protein disulfide bonds with tris(hydroxypropyl)phosphine resulted in virtually complete immobilization of the SHGFP-MUC5AC/CK intragranular pool. However, when activity of the vacuolar H+-ATPase was also inhibited, disulfide reduction decreased SHGFP-MUC5AC/CK t((1/2)) while diminishing its intraluminal concentration. Similar FRAP profiles were observed in granules that remained in the cells after the addition of a mucin secretagogue. Taken together these results suggest that: (a) the relative content of O-glycans and intragranular anionic groups is crucial for protein diffusion through the intragranular meshwork; (b) protein-protein, rather than carbohydrate-mediated, interactions are responsible for binding of SHGFP-MUC5AC/CK to the immobile fraction, although the degree of matrix O-glycosylation and sialylation affects such interactions; (c) intragranular organization does not depend on covalent multimerization of mucins or the presence of native disulfide bonds in the intragranular mucin/proteins, but rather on specific protein-mediated interactions that are important during the early stages of mucin matrix condensation; (d) alterations of the intragranular matrix precede granule discharge, which can be partial and, accordingly, does not necessarily involve the disappearance of the granule.
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| pubmed:grant | |
| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/CASP3 protein, human,
http://linkedlifedata.com/resource/pubmed/chemical/CASP7 protein, human,
http://linkedlifedata.com/resource/pubmed/chemical/Carbohydrates,
http://linkedlifedata.com/resource/pubmed/chemical/Casp3 protein, mouse,
http://linkedlifedata.com/resource/pubmed/chemical/Casp7 protein, mouse,
http://linkedlifedata.com/resource/pubmed/chemical/Caspase 3,
http://linkedlifedata.com/resource/pubmed/chemical/Caspase 7,
http://linkedlifedata.com/resource/pubmed/chemical/Caspases,
http://linkedlifedata.com/resource/pubmed/chemical/Chlorates,
http://linkedlifedata.com/resource/pubmed/chemical/Disulfides,
http://linkedlifedata.com/resource/pubmed/chemical/Dithiothreitol,
http://linkedlifedata.com/resource/pubmed/chemical/Green Fluorescent Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/MUC5AC protein, human,
http://linkedlifedata.com/resource/pubmed/chemical/Muc5ac protein, mouse,
http://linkedlifedata.com/resource/pubmed/chemical/Mucin 5AC,
http://linkedlifedata.com/resource/pubmed/chemical/Mucins,
http://linkedlifedata.com/resource/pubmed/chemical/Polysaccharides,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/sodium chlorate
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| pubmed:status |
MEDLINE
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| pubmed:month |
Feb
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| pubmed:issn |
0021-9258
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
24
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| pubmed:volume |
281
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
4844-55
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| pubmed:dateRevised |
2008-11-21
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| pubmed:meshHeading |
pubmed-meshheading:16377632-Animals,
pubmed-meshheading:16377632-Apoptosis,
pubmed-meshheading:16377632-Carbohydrates,
pubmed-meshheading:16377632-Caspase 3,
pubmed-meshheading:16377632-Caspase 7,
pubmed-meshheading:16377632-Caspases,
pubmed-meshheading:16377632-Cell Line,
pubmed-meshheading:16377632-Chlorates,
pubmed-meshheading:16377632-Diffusion,
pubmed-meshheading:16377632-Disulfides,
pubmed-meshheading:16377632-Dithiothreitol,
pubmed-meshheading:16377632-Glycosylation,
pubmed-meshheading:16377632-Goblet Cells,
pubmed-meshheading:16377632-Green Fluorescent Proteins,
pubmed-meshheading:16377632-Humans,
pubmed-meshheading:16377632-Mice,
pubmed-meshheading:16377632-Microscopy, Confocal,
pubmed-meshheading:16377632-Mucin 5AC,
pubmed-meshheading:16377632-Mucins,
pubmed-meshheading:16377632-NIH 3T3 Cells,
pubmed-meshheading:16377632-Polysaccharides,
pubmed-meshheading:16377632-Protein Binding,
pubmed-meshheading:16377632-Protein Processing, Post-Translational,
pubmed-meshheading:16377632-Recombinant Fusion Proteins,
pubmed-meshheading:16377632-Time Factors
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| pubmed:year |
2006
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| pubmed:articleTitle |
Mucin granule intraluminal organization in living mucous/goblet cells. Roles of protein post-translational modifications and secretion.
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| pubmed:affiliation |
Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina, Chapel Hill, North Carolina 27599-7248, USA. juan_vilar@med.unc.edu
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| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't,
Research Support, N.I.H., Extramural
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