Linked Life Data

10220327

Source:http://linkedlifedata.com/resource/pubmed/id/10220327

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1999-5-14
pubmed:abstractText
Assembly of the heterotrimeric procollagen I molecule is initiated by interactions between the carboxyl propeptide domains of the completed nascent pro alpha chains. The [pro alpha 1(I)]2[pro alpha 2(I)] heterotrimer is the predominant molecule, with much smaller amounts of stable [pro alpha 1(I)]3 homotrimer also being formed. However, the [pro alpha 2(1)]3 homotrimer has not been detected, raising questions as to the mechanism of chain assembly and why [pro alpha2(1)]3 homotrimers are not formed. These questions have been examined here by expressing the intact and amino- or carboxyl-terminal truncated C-propeptides of the pro alpha chains recombinantly in bacteria and in a coupled transcription/translation reticulocyte lysate system. Their interactions were studied in vitro by binding analyses and in vivo by using the yeast two-hybrid system. The C-pro alpha 1(I) interacted with itself, and with C-pro alpha 2(I), as expected. Surprisingly, the C-pro alpha 2(I) also interacted with itself, both in vitro and in vivo. While the interaction of C-pro alpha 2(I) with itself and C-pro alpha 1(I) in vitro was strong, these interactions were weaker in vivo. Deletion of 36 amino acids from the C-terminal domain of C-pro alpha 1 had no effect on its binding to intact self or intact C-pro alpha 2, but the same deletion in C-pro alpha 2 completely abolished its binding to intact C-pro alpha 2 and to C-pro alpha 1. Comparable N-terminal deletions in C-pro alpha 1 or C-pro alpha 2 diminished, but did not abolish, their binding to intact C-pro alpha 1 and C-pro alpha 2. In the yeast two-hybrid system, C-pro alpha 2 interacted with itself more weakly than with C-pro alpha 1. Molecular modeling and circular dichroism analyses showed that C-pro alpha 1 and C-pro alpha 2 have different folded structures and stability. Studies with antibodies specific to the C-pro alpha1 and alpha2 peptides showed them to precipitate different, specific, and distinct cell proteins from fibroblast lysates. The C-pro alpha 2(I) antibody complexed with more cell proteins. We hypothesize that the lack of pro alpha 2(I) homotrimers is not due to the inability of the C-pro alpha 2(I) to interact with itself, but rather to the competing presence of other cell proteins. The specificity of these interactions may reside in conformational differences in N- and C-terminal sequences of the two propeptides or in their different folding patterns.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
38
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5401-11
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:10220327-Amino Acid Sequence, pubmed-meshheading:10220327-Animals, pubmed-meshheading:10220327-Blotting, Western, pubmed-meshheading:10220327-Cell Line, pubmed-meshheading:10220327-Cell-Free System, pubmed-meshheading:10220327-Circular Dichroism, pubmed-meshheading:10220327-Disulfides, pubmed-meshheading:10220327-Escherichia coli, pubmed-meshheading:10220327-Genetic Vectors, pubmed-meshheading:10220327-Humans, pubmed-meshheading:10220327-Models, Molecular, pubmed-meshheading:10220327-Molecular Sequence Data, pubmed-meshheading:10220327-Peptide Fragments, pubmed-meshheading:10220327-Precipitin Tests, pubmed-meshheading:10220327-Procollagen, pubmed-meshheading:10220327-Protein Folding, pubmed-meshheading:10220327-Protein Processing, Post-Translational, pubmed-meshheading:10220327-Rabbits, pubmed-meshheading:10220327-Recombinant Proteins, pubmed-meshheading:10220327-Saccharomyces cerevisiae
pubmed:year
1999
pubmed:articleTitle
Assembly of the type 1 procollagen molecule: selectivity of the interactions between the alpha 1(I)- and alpha 2(I)-carboxyl propeptides.
pubmed:affiliation
Division of Oral Biology, Northwestern University Dental School, Chicago, Illinois 60611, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.