Linked Life Data

20886905

Source:http://linkedlifedata.com/resource/pubmed/id/20886905

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
44
pubmed:dateCreated
2011-4-19
pubmed:abstractText
Human immunodeficiency virus type 1 (HIV-1) encodes a polypeptide called Gag that is capable of forming virus-like particles (VLPs) in vitro in the absence of other cellular or viral constituents. During the late phase of HIV-1 infection, Gag polyproteins are transported to the plasma membrane (PM) for assembly. A combination of in vivo, in vitro, and structural studies have shown that Gag targeting and assembly on the PM are mediated by specific interactions between the myristoylated matrix [myr(+)MA] domain of Gag and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. Exposure of the MA myristyl (myr) group is triggered by PI(4,5)P2 binding and is enhanced by factors that promote protein self-association. In the studies reported here, we demonstrate that myr exposure in MA is modulated by pH. Our data show that deprotonation of the His89 imidazole ring in myr(+)MA destabilizes the salt bridge formed between His89(H?2) and Glu12(COO-), leading to tight sequestration of the myr group and a shift in the equilibrium from trimer to monomer. Furthermore, we show that oligomerization of a Gag-like construct containing matrix-capsid is also pH-dependent. Disruption of the His?Glu salt bridge by single-amino acid substitutions greatly altered the myr-sequestered?myr-exposed equilibrium. In vivo intracellular localization data revealed that the H89G mutation retargets Gag to intracellular compartments and severely inhibits virus production. Our findings reveal that the MA domain acts as a “pH sensor” in vitro, suggesting that the effect of pH on HIV-1 Gag targeting and binding to the PM warrants investigation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
1520-4995
pubmed:author
pubmed:issnType
Electronic
pubmed:day
9
pubmed:volume
49
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9551-62
pubmed:dateRevised
2011-11-14
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Myristate exposure in the human immunodeficiency virus type 1 matrix protein is modulated by pH.
pubmed:affiliation
Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural, Research Support, N.I.H., Intramural