Linked Life Data

11344168

Source:http://linkedlifedata.com/resource/pubmed/id/11344168

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
2001-7-9
pubmed:abstractText
The TIM23 complex mediates import into mitochondria of nuclear encoded preproteins with a matrix-targeting signal. It is composed of the integral membrane proteins Tim17 and Tim23 and the peripheral membrane protein Tim44, which recruits mitochondrial Hsp70 to the sites of protein import. We have analyzed the functions of these constituents using a combined genetic and biochemical approach. Depletion of either Tim17 or Tim23 led to loss of import competence of mitochondria and to a reduction in the number of preprotein-conducting channels. Upon depletion of Tim44, mitochondria also lost their ability to import proteins but maintained normal numbers of import channels. In the absence of Tim44 precursor protein was specifically recognized. The presequence was translocated in a Delta psi-dependent manner across the inner membrane and cleaved by matrix-processing peptidase. However, the preprotein did not move further into the matrix but rather underwent retrograde sliding out of the TIM23 complex. Thus, the TIM23 complex is composed of functionally independent modules. Tim17 and Tim23 are necessary for initiating translocation, whereas Tim44 and mitochondrial Hsp70 are indispensable for complete transport of preproteins and for unfolding of folded domains of preproteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
25856-61
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Modular structure of the TIM23 preprotein translocase of mitochondria.
pubmed:affiliation
Institut für Physiologische Chemie der Universität München, Goethestrasse 33, 80336 München, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't