Linked Life Data

11576437

Source:http://linkedlifedata.com/resource/pubmed/id/11576437

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-9-28
pubmed:abstractText
A deletion and mutagenesis study was performed on the mitochondrial presequence of the beta-subunit of the F(1)-ATP synthase from Nicotiana plumbaginifolia linked to the green fluorescent protein (GFP). The various constructs were tested in vivo by transient expression in tobacco protoplasts. GFP distribution in transformed cells was analysed in situ by confocal microscopy, and in vitro in subcellular fractions by Western blotting. Despite its being highly conserved in different species, deletion of the C-terminal region (residues 48-54) of the presequence did not affect mitochondrial import. Deletion of the conserved residues 40-47 and the less conserved intermediate region (residues 18-39) resulted in 60% reduction in GFP import, whereas mutation of conserved residues within these regions had little effect. Further shortening of the presequence progressively reduced import, with the construct retaining the predicted N-terminal amphiphilic alpha-helix (residues 1-12) being unable to mediate mitochondrial import. However, point mutation showed that this last region plays an important role through its basic residues and amphiphilicity, but also through its hydrophobic residues. Replacing Arg4 and Arg5 by alanine residues and shifting the Arg5 and Leu6 (in order to disturb amphiphilicity) resulted in reduction of the presequence import efficiency. The most dramatic effects were seen with single or double mutations of the four Leu residues (positions 5, 6, 10 and 11), which resulted in marked reduction or abolition of GFP import, respectively. We conclude that the N-terminal helical structure of the presequence is necessary but not sufficient for efficient mitochondrial import, and that its hydrophobic residues play an essential role in in vivo mitochondrial targeting.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0960-7412
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
539-49
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11576437-Amino Acid Sequence, pubmed-meshheading:11576437-Conserved Sequence, pubmed-meshheading:11576437-Green Fluorescent Proteins, pubmed-meshheading:11576437-Leucine, pubmed-meshheading:11576437-Luminescent Proteins, pubmed-meshheading:11576437-Mitochondria, pubmed-meshheading:11576437-Molecular Sequence Data, pubmed-meshheading:11576437-Mutagenesis, Site-Directed, pubmed-meshheading:11576437-Plant Proteins, pubmed-meshheading:11576437-Protein Precursors, pubmed-meshheading:11576437-Protein Processing, Post-Translational, pubmed-meshheading:11576437-Protein Sorting Signals, pubmed-meshheading:11576437-Protein Structure, Secondary, pubmed-meshheading:11576437-Protein Transport, pubmed-meshheading:11576437-Proton-Translocating ATPases, pubmed-meshheading:11576437-Recombinant Fusion Proteins, pubmed-meshheading:11576437-Saccharomyces cerevisiae, pubmed-meshheading:11576437-Sequence Deletion, pubmed-meshheading:11576437-Tobacco, pubmed-meshheading:11576437-Transformation, Genetic
pubmed:year
2001
pubmed:articleTitle
Hydrophobic residues within the predicted N-terminal amphiphilic alpha-helix of a plant mitochondrial targeting presequence play a major role in in vivo import.
pubmed:affiliation
Unité de biochimie physiologique, Université catholique de Louvain, Croix du Sud 2-20, B-1348 Louvain-la-Neuve, Belgium.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't