Linked Life Data

17959599

Source:http://linkedlifedata.com/resource/pubmed/id/17959599

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
2007-12-17
pubmed:abstractText
It is not known why leader peptides are removed by the mitochondrial processing peptidase after import into the matrix space. The leaders of yeast aldehyde dehydrogenase (pALDH) and malate dehydrogenase were mutated so that they would not be processed after import. The recombinant nonprocessed precursor of yeast pALDH possessed a similar specific activity as the corresponding mature form but was much less stable. The nonprocessed pALDH was transformed into a yeast strain missing ALDHs. The transformed yeast grew slowly on ethanol as the sole carbon source showing that the nonprocessed precursor was functional in vivo. Western blot analysis showed that the amount of precursor was 15-20% of that found in cells transformed with the native enzyme. Pulse-chase experiments revealed that the turnover rate for the nonprocessed precursor was greater than that of the mature protein indicating that the nonprocessed precursor could have been degraded. By using carbonyl cyanide m-chlorophenylhydrazone, we showed that the nonprocessed precursor was degraded in the matrix space. The nonprocessed precursor forms of precursor yeast malate dehydrogenase and rat liver pALDH also were degraded in the matrix space of HeLa cell mitochondria faster than their corresponding mature forms. In the presence of o-phenanthroline, an inhibitor of mitochondrial processing peptidase, the wild type precursor was readily degraded in the matrix space. Collectively, this study showed that the precursor form is less stable in the matrix space than is the mature form and provides an explanation for why the leader peptide is removed from the precursors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
37266-75
pubmed:meshHeading
pubmed-meshheading:17959599-Aldehyde Dehydrogenase, pubmed-meshheading:17959599-Animals, pubmed-meshheading:17959599-HeLa Cells, pubmed-meshheading:17959599-Humans, pubmed-meshheading:17959599-Liver, pubmed-meshheading:17959599-Malate Dehydrogenase, pubmed-meshheading:17959599-Metalloendopeptidases, pubmed-meshheading:17959599-Mitochondria, pubmed-meshheading:17959599-Mitochondrial Proteins, pubmed-meshheading:17959599-Protein Precursors, pubmed-meshheading:17959599-Protein Processing, Post-Translational, pubmed-meshheading:17959599-Protein Sorting Signals, pubmed-meshheading:17959599-Protein Transport, pubmed-meshheading:17959599-Rats, pubmed-meshheading:17959599-Recombinant Proteins, pubmed-meshheading:17959599-Saccharomyces cerevisiae, pubmed-meshheading:17959599-Saccharomyces cerevisiae Proteins
pubmed:year
2007
pubmed:articleTitle
Precursor protein is readily degraded in mitochondrial matrix space if the leader is not processed by mitochondrial processing peptidase.
pubmed:affiliation
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907-2063, USA. mukhopad@purdue.edu
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural