Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-7-13
pubmed:abstractText
Calreticulin is the major high capacity, low affinity Ca2+ binding protein localized within the endoplasmic reticulum. It functions as a reservoir for triggered release of Ca2+ by the endoplasmic reticulum and is thus integral to eukaryotic signal transduction pathways involving Ca2+ as a second messenger. The early branching photosynthetic protist Euglena gracilis is shown to possess calreticulin as its major high capacity Ca2+ binding protein. The protein was purified, microsequenced and cloned. Like its homologues from higher eukaryotes, calreticulin from Euglena possesses a short signal peptide for endoplasmic reticulum import and the C-terminal retention signal KDEL, indicating that these components of the eukaryotic protein routing apparatus were functional in their present form prior to divergence of the euglenozoan lineage. A gene phylogeny for calreticulin and calnexin sequences in the context of eukaryotic homologues indicates i) that these Ca2+ binding endoplasmic reticulum proteins descend from a gene duplication that occurred in the earliest stages of eukaryotic evolution and furthermore ii) that Euglenozoa express the calreticulin protein of the kinetoplastid (trypanosomes and their relatives) lineage, rather than that of the eukaryotic chlorophyte which gave rise to Euglena's plastids. Evidence for conservation of endoplasmic reticulum routing and Ca2+ binding function of calreticulin from Euglena traces the functional history of Ca2+ second messenger signal transduction pathways deep into eukaryotic evolution.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1066-5234
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
307-13
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9627991-Amino Acid Sequence, pubmed-meshheading:9627991-Animals, pubmed-meshheading:9627991-Base Sequence, pubmed-meshheading:9627991-Calcium, pubmed-meshheading:9627991-Calcium-Binding Proteins, pubmed-meshheading:9627991-Calreticulin, pubmed-meshheading:9627991-Cell Fractionation, pubmed-meshheading:9627991-Centrifugation, Density Gradient, pubmed-meshheading:9627991-Cloning, Molecular, pubmed-meshheading:9627991-DNA, Complementary, pubmed-meshheading:9627991-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:9627991-Endoplasmic Reticulum, pubmed-meshheading:9627991-Euglena gracilis, pubmed-meshheading:9627991-Evolution, Molecular, pubmed-meshheading:9627991-Genes, Protozoan, pubmed-meshheading:9627991-Molecular Sequence Data, pubmed-meshheading:9627991-Phylogeny, pubmed-meshheading:9627991-Ribonucleoproteins, pubmed-meshheading:9627991-Sequence Analysis, DNA, pubmed-meshheading:9627991-Signal Transduction
pubmed:articleTitle
Functional conservation of calreticulin in Euglena gracilis.
pubmed:affiliation
Dipartimento di Biologia, Università di Padova, Italy.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't