Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-10-6
pubmed:databankReference
pubmed:abstractText
Sieve elements in the phloem of most angiosperms contain proteinaceous filaments and aggregates called P-protein. In the genus Cucurbita, these filaments are composed of two major proteins: PP1, the phloem filament protein, and PP2, the phloem lactin. The gene encoding the phloem filament protein in pumpkin (Cucurbita maxima Duch.) has been isolated and characterized. Nucleotide sequence analysis of the reconstructed gene gPP1 revealed a continuous 2430 bp protein coding sequence, with no introns, encoding an 809 amino acid polypeptide. The deduced polypeptide had characteristics of PP1 and contained a 15 amino acid sequence determined by N-terminal peptide sequence analysis of PP1. The sequence of PP1 was highly repetitive with four 200 amino acid sequence domains containing structural motifs in common with cysteine proteinase inhibitors. Expression of the PP1 gene was detected in roots, hypocotyls, cotyledons, stems, and leaves of pumpkin plants. PP1 and its mRNA accumulated in pumpkin hypocotyls during the period of rapid hypocotyl elongation after which mRNA levels declined, while protein levels remained elevated. PP1 was immunolocalized in slime plugs and P-protein bodies in sieve elements of the phloem. Occasionally, PP1 was detected in companion cells. PP1 mRNA was localized by in situ hybridization in companion cells at early stages of vascular differentiation. The developmental accumulation and localization of PP1 and its mRNA paralleled the phloem lactin, further suggesting an interaction between these phloem-specific proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0960-7412
pubmed:author
pubmed:issnType
Print
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
49-61
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:9263452-Amino Acid Sequence, pubmed-meshheading:9263452-Base Sequence, pubmed-meshheading:9263452-Consensus Sequence, pubmed-meshheading:9263452-Conserved Sequence, pubmed-meshheading:9263452-Cysteine Proteinase Inhibitors, pubmed-meshheading:9263452-DNA, Plant, pubmed-meshheading:9263452-Gene Expression Regulation, Plant, pubmed-meshheading:9263452-Genes, Plant, pubmed-meshheading:9263452-MAP Kinase Kinase Kinases, pubmed-meshheading:9263452-Molecular Sequence Data, pubmed-meshheading:9263452-Plant Proteins, pubmed-meshheading:9263452-Protein Biosynthesis, pubmed-meshheading:9263452-Protein Kinases, pubmed-meshheading:9263452-Protein Structure, Secondary, pubmed-meshheading:9263452-RNA, Messenger, pubmed-meshheading:9263452-Sequence Alignment, pubmed-meshheading:9263452-Sequence Homology, Amino Acid, pubmed-meshheading:9263452-Transcription, Genetic, pubmed-meshheading:9263452-Vegetables
pubmed:year
1997
pubmed:articleTitle
Molecular characterization of a phloem-specific gene encoding the filament protein, phloem protein 1 (PP1), from Cucurbita maxima.
pubmed:affiliation
Department of Plant Sciences, University of Arizona, Tucson 86712, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S.