Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
2006-5-1
pubmed:abstractText
Activity of Ho, the yeast mating switch endonuclease, is restricted to a narrow time window of the cell cycle. Ho is unstable and despite being a nuclear protein is exported to the cytoplasm for proteasomal degradation. We report here the molecular basis for the highly efficient nuclear import of Ho and the relation between its short half-life and passage through the nucleus. The Ho nuclear import machinery is functionally redundant, being based on two bipartite nuclear localization signals, recognized by four importins of the ribosomal import system. Ho degradation is regulated by the DNA damage response and Ho retained in the cytoplasm is stabilized, implying that Ho acquires its crucial degradation signals in the nucleus. Ho arose by domestication of a fungal VMA1 intein. A comparison of the primary sequences of Ho and fungal VMA1 inteins shows that the Ho nuclear localization signals are highly conserved in all Ho proteins, but are absent from VMA1 inteins. Thus adoption of a highly efficient import strategy occurred very early in the evolution of Ho. This may have been a crucial factor in establishment of homothallism in yeast, and a key event in the rise of the Saccharomyces sensu stricto.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
281
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12218-26
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Nuclear import of ho endonuclease utilizes two nuclear localization signals and four importins of the ribosomal import system.
pubmed:affiliation
Department of Life Sciences, Ben Gurion University of the Negev, P. O. Box 653, 84105 Beersheba, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't