Linked Life Data

11849641

Source:http://linkedlifedata.com/resource/pubmed/id/11849641

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-3-6
pubmed:databankReference
pubmed:abstractText
Leishmania mexicana, like other trypanosomatid parasites, is a purine auxotroph and must obtain these essential nutrients from its sandfly and mammalian hosts. A single copy gene encoding its unique externally oriented, surface membrane, purine salvage enzyme 3'-nucleotidase/nuclease, was isolated. Structural features of the deduced protein included: an endoplasmic reticulum-directed signal peptide, several conserved class I catalytic and metal co-factor (Zn(2+)) binding domains, transmembrane anchor sequence and a C-terminal cytoplasmic tail. 3'-Nucleotidase/nuclease gene (mRNA) and protein (enzyme activity) expression were examined in three different L. mexicana developmental forms: procyclic promastigotes, metacyclic promastigotes and amastigotes. Results of both approaches demonstrated that the 3'-nucleotidase/nuclease was a stage-specific enzyme, being expressed by promastigote forms (stages restricted to the insect vector), but not by amastigotes (which produce disease in mammalian hosts). Starvation of these parasites for purines resulted in the significant up-regulation of both 3'-nucleotidase/nuclease mRNA and enzyme activity in promastigotes, but not in amastigotes. These results underscore the critical role that the 3'-nucleotidase/nuclease must play in purine salvage during the rapid multiplicative expansion of the parasite population within its insect vector. To our knowledge, the L. mexicana 3'-nucleotidase/nuclease is the first example of a nutrient-induced and developmentally regulated enzyme in any parasitic protozoan.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0020-7519
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
449-59
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Developmentally regulated expression of a cell surface class I nuclease in Leishmania mexicana.
pubmed:affiliation
Division of Molecular Biology and Immunology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't