Linked Life Data

17462029

Source:http://linkedlifedata.com/resource/pubmed/id/17462029

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-4-27
pubmed:abstractText
The effect of osmotic stress on the intracellular diffusion of proteins in Escherichia coli was studied, using a pulsed version of fluorescence recovery after photo-bleaching, pulsed-FRAP. This method employs sequences of laser pulses which only partly bleach the fluorophores in a cell. Because the cell size and geometry are taken into account, pulsed-FRAP enables to measure diffusion in very small cells of different shapes. We found that upon an osmotic upshock from 0.15 to 0.6 Osm, imposed by NaCl or sorbitol, the apparent intracellular diffusion (D) of mobile green fluorescent protein (GFP) decreased from 3.2 to 0.4 microm(2) s(-1), whereas the membrane permeable glycerol had no effect. Exposing E. coli cells to higher osmolalities (> 0.6 Osm) led to compartmentalization of the GFP into discrete pools, from where the GFP could not escape. Although free diffusion through the cell was hindered, the mobility of GFP in these pools was still relatively high (D approximately 0.4 microm(2) s(-1)). The presence of osmoprotectants restored the effect of osmotic stress on the protein mobility and apparent compartmentalization. Also, lowering the osmolality from 0.6 Osm back to 0.15 Osm restored the mobility of GFP. The implications of these findings in terms of heterogeneities and diffusive barriers inside the cell are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
64
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
858-71
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Protein mobility and diffusive barriers in Escherichia coli: consequences of osmotic stress.
pubmed:affiliation
Biochemistry Department, Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't