Molecular and structural analyses of a novel temperature stress-induced lipocalin from wheat and Arabidopsis.
Two cDNAs corresponding to a novel lipocalin were identified from wheat and Arabidopsis. The two cDNAs designated Tatil for Triticum aestivum L. temperature-induced lipocalin and Attil for Arabidopsis thaliana temperature-induced lipocalin encode polypeptides of 190 and 186 amino acids respectively. Structure analyses indicated the presence of the three structurally conserved regions that characterize lipocalins. Sequence analyses revealed that this novel class of plant lipocalin shares homology with three evolutionarily related lipocalins: the mammalian apolipoprotein D (ApoD), the bacterial lipocalin and the insect Lazarillo. The comparison of the putative tertiary structures of both the human ApoD and the wheat TaTIL suggest that the two proteins differ in membrane attachment and ligand interaction. Northern analyses demonstrated that Tatil and Attil transcripts are upregulated during cold acclimation and heat-shock treatment. The putative functions of this novel class of plant lipocalins during temperature stresses are discussed.
Frenette Charron
Jean Benoit
JB
Département des Sciences Biologiques, Université du Québec à Montréal, P.O. Box 8888, Succ. "Centre-Ville", Montréal, QC, Canada.
Breton
Ghislain
G
Badawi
Mohamed
M
Sarhan
Fathey
F
D000595:Amino Acid Sequence; D000818:Animals; D001053:Apolipoproteins / Q000737:chemistry / Q000235:genetics; D053399:Apolipoproteins D; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003080:Cold Temperature; D006358:Hot Temperature; D006801:Humans; D054834:Lipocalins; D008074:Lipoproteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D017385:Sequence Homology; D017386:Sequence Homology, Amino Acid; D014908:Triticum / Q000378:metabolism*
D001053:Apolipoproteins; D053399:Apolipoproteins D; D029681:Arabidopsis Proteins; C460762:At5g58070 protein, Arabidopsis; D054834:Lipocalins; D008074:Lipoproteins; D010940:Plant Proteins