Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2005-4-25
pubmed:abstractText
Mitochondria are remarkably plastic organelles constantly changing their shape to fulfil their various functional activities. Although the osmotic movement of water into and out of the mitochondrion is central for its morphology and activity, the molecular mechanisms and the pathways for water transport across the inner mitochondrial membrane (IMM), the main barrier for molecules moving into and out of the organelle, are completely unknown. Here, we show the presence of a member of the aquaporin family of water channels, AQP8, and demonstrate the strikingly high water permeability (Pf) characterizing the rat liver IMM. Immunoblotting, electron microscopy, and biophysical studies show that the largest mitochondria feature the highest AQP8 expression and IMM Pf. AQP8 was also found in the mitochondria of other organs, whereas no other known aquaporins were seen. The osmotic water transport of liver IMM was partially inhibited by the aquaporin blocker Hg2+, while the related activation energy remained low, suggesting the presence of a Hg2+-insensitive facilitated pathway in addition to AQP8. It is suggested that AQP8-mediated water transport may be particularly important for rapid expansions of mitochondrial volume such as those occurring during active oxidative phosphorylation and those following apoptotic signals.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
29
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
17149-53
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15749715-Animals, pubmed-meshheading:15749715-Apoptosis, pubmed-meshheading:15749715-Aquaporins, pubmed-meshheading:15749715-Hepatocytes, pubmed-meshheading:15749715-Immunoblotting, pubmed-meshheading:15749715-Immunohistochemistry, pubmed-meshheading:15749715-Intracellular Membranes, pubmed-meshheading:15749715-Ion Channels, pubmed-meshheading:15749715-Light, pubmed-meshheading:15749715-Liver, pubmed-meshheading:15749715-Male, pubmed-meshheading:15749715-Mercury, pubmed-meshheading:15749715-Microscopy, Electron, pubmed-meshheading:15749715-Mitochondria, pubmed-meshheading:15749715-Osmosis, pubmed-meshheading:15749715-Oxygen, pubmed-meshheading:15749715-Permeability, pubmed-meshheading:15749715-Phosphorylation, pubmed-meshheading:15749715-Rats, pubmed-meshheading:15749715-Rats, Wistar, pubmed-meshheading:15749715-Scattering, Radiation, pubmed-meshheading:15749715-Subcellular Fractions, pubmed-meshheading:15749715-Time Factors, pubmed-meshheading:15749715-Water
pubmed:year
2005
pubmed:articleTitle
The inner mitochondrial membrane has aquaporin-8 water channels and is highly permeable to water.
pubmed:affiliation
Dipartimento di Fisiologia Generale ed Ambientale and Dipartimento di Zoologia, Laboratorio di Istologia e di Anatomia Comparata, Università degli Studi di Bari, 70126 Bari, Italy. calamita@biologia.uniba.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't