Linked Life Data

3283145

Source:http://linkedlifedata.com/resource/pubmed/id/3283145

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1988-6-7
pubmed:abstractText
The major hepatitis B virus (HBV) core protein is a viral structural protein involved in nucleic acid binding. Its coding sequence contains an extension of 29 codons (the "precore" region) at the amino terminus of the protein which is present in a fraction of the viral transcripts. This region is evolutionarily conserved among mammalian and avian HBVs, suggesting it has functional importance, although at least for duck HBV it has been shown to be nonessential for replication of infectious virions. Using in vitro assays for protein translocation across the endoplasmic reticulum membrane, we found that the precore region of the HBV genome encodes a signal sequence. This signal sequence was recognized by signal recognition particle, which targeted the nascent precore protein to the endoplasmic reticulum membrane with efficiencies comparable to those of other mammalian secretory proteins. A 19-amino acid signal peptide was removed by signal peptidase on the lumenal side of the microsomal membrane, generating a protein similar to the HBV major core protein, but containing 10 additional amino acids from the precore region at its amino terminus. Surprisingly, we found that 70-80% of this signal peptidase-cleaved product was localized on the cytoplasmic side of the microsomal vesicles and was not associated with the membranes. We conclude that translocation was aborted by an unknown mechanism, then the protein disengaged from the translocation machinery and was released back into the cytoplasm. Thus, a cytoplasmically disposed protein was created whose amino terminus resulted from signal peptidase cleavage. The remaining 20-30% appeared to be completely translocated into the lumen of the microsomes. A deletion mutant lacking the carboxy-terminal nucleic acid binding domain of the precore protein was similarly partitioned between the lumen of the microsomes and the cytoplasmic compartment, indicating that this highly charged domain is not responsible for the aborted translocation. We discuss the implications of our findings for the protein translocation process and suggest a possible role in the virus life cycle.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-2410139, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-2431165, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-2431277, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-2828872, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-2995835, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-3006057, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-3012638, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-3023891, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-3041052, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-3298258, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-3543403, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-3546728, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-3745217, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6096101, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6189903, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6197610, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6313206, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6379599, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6395892, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6423828, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6656637, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6656655, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6855576, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6929499, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-6938958, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-7309795, http://linkedlifedata.com/resource/pubmed/commentcorrection/3283145-7309797
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9525
pubmed:author
pubmed:issnType
Print
pubmed:volume
106
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1093-104
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Targeting of the hepatitis B virus precore protein to the endoplasmic reticulum membrane: after signal peptide cleavage translocation can be aborted and the product released into the cytoplasm.
pubmed:affiliation
Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't