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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
1990-11-15
pubmed:databankReference
pubmed:abstractText
Ferritin is a large multisubunit protein that stores iron in plants, animals, and bacteria. In animals, the protein is mainly cytoplasmic and is highly conserved, while in plants ferritin is found in chloroplasts and other plastids. Ferritin is synthesized in plants as a larger precursor of the mature subunit. There is no sequence information for ferritin from plants, except an NH2-terminal peptide of 35 residues which shows little similarity to any known ferritin sequences or transit peptides (Laulhere, J. P., Laboure, A. M., and Briat, J. F. (1989) J. Biol. Chem. 264, 3629-3635). To understand the genetic origin and the location of ferritin synthesis in plant cells, as well as the structure of ferritin from plants, we have sequenced both CNBr peptides from pea seed ferritin and nucleotides of a soybean hypocotyl ferritin cDNA, identified using a frog ferritin cDNA as a probe. Comparison of pea and soybean sequences showed an identity of 89%. Alignment of the plant ferritin sequences with animal ferritins showed 55-65% sequence identity in the common regions. However, a peptide of 28 amino acids extended the NH2 terminus of the plant ferritins. Furthermore, the cDNA encoded additional amino acids which appear to be a transit peptide. None of the sequences in soybean ferritin were found in the tobacco chloroplast genome, suggesting, as does the transit peptide, a nuclear location of ferritin gene(s) in plants. Plant ferritin mRNA is 400-500 nucleotides longer than animal ferritin mRNAs, a difference accounted for in part by the extra peptides encoded. The size of soybean ferritin mRNA was constant in different tissues but expression varied in different tissues (leaf greater than hypocotyl). Thus, higher plants and animal ferritins display sequence homology and differential tissue expression. An ancient, common progenitor apparently gave rise to contemporary eukaryotic ferritins after specific modifications, e.g. transport to plasmids.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
265
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18339-44
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Evidence for conservation of ferritin sequences among plants and animals and for a transit peptide in soybean.
pubmed:affiliation
Department of Biochemistry, North Carolina State University, Raleigh 27695-7622.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't