Linked Life Data

8281191

Source:http://linkedlifedata.com/resource/pubmed/id/8281191

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1994-2-17
pubmed:databankReference
pubmed:abstractText
A general amino acid permease cDNA (AAP2) was isolated from Arabidopsis by complementation of a yeast mutant defective in citrulline uptake. Direct transport measurements in yeast show that the protein mediates uptake of L-[14C]-citrulline and L-[14C]-proline. Detailed analyses of the substrate specificity by competition studies demonstrate that all proteogenic amino acids are recognized by the carrier, including those that represent the major transport forms of reduced nitrogen in many species, i.e. glutamine, glutamate and asparagine. Thus, AAP2 is less selective as compared with AAP1 and transports basic amino acids such as histidine as shown by expression in a histidine transport-deficient yeast strain. The predicted polypeptide of 53 kDa is highly hydrophobic with 12 putative membrane-spanning regions and shows significant homologies to the Arabidopsis broad specificity permease AAP1, and a limited homology to bacterial branched chain amino acid transporters, but not to any other known proteins. Alterations in the charged residues as compared with AAP1 in four regions might be involved in the difference in selectivity towards basic amino acids. Both genes are highly expressed in developing pods indicating a role in supplying the developing seeds with reduced nitrogen. AAP2 is selectively expressed in the stem and might therefore play a role in xylem-to-phloem transfer of amino acids during seed filling. Furthermore in situ hybridization shows that both genes are expressed in the vascular system of cotyledons in developing seedlings.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0960-7412
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:geneSymbol
AAP2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
993-1002
pubmed:dateRevised
2006-11-7
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Differential expression of two related amino acid transporters with differing substrate specificity in Arabidopsis thaliana.
pubmed:affiliation
Institut für Genbiologische Forschung, Berlin, Germany.
pubmed:publicationType
Journal Article