MdAP, a novel protein in apple, is associated with the major allergen Mal d 1.
Mal d 1, an 18-kDa intracellular pathogenesis-related protein (PR-10), has been known since long as the major apple allergen in Middle and Northern Europe. However, its biological function, as that of many other PR-10 proteins, is still unknown. In order to identify proteins putatively interacting with Mal d 1, an expression library of Malus domestica was screened using the yeast-two-hybrid (Y2H) system. A novel protein binding to two isoforms of Mal d 1 being used as 'bait' was isolated. The deduced amino acid sequence from the corresponding full-length cDNA of the predicted Mal d 1-Associated-Protein (MdAP) do not display any homology to known proteins, but shares 45% identity with a 'hypothetical protein' in Arabidopsis thaliana. Southern analysis of the apple genome indicated that MdAP, comprising 190 amino acids, is encoded by a single gene. The expression pattern of the 1-kb MdAP transcript resembled the expression profile of the different Mal d 1 isoforms in various apple organs, however at a much lower level. Furthermore, a huge variation in transcription levels of Mal d 1 isoforms was observed in apple tissue. For both, Mal d 1 and MdAP highest amounts of mRNAs were measured in ripe fruits and significantly lower amounts in vegetative tissue by quantitative reverse transcription-polymerase chain reaction (RT-PCR).
Puehringer
Helene Maria
HM
Plant Biotechnology Unit, Institute of Applied Microbiology, University of Natural Resources and Applied Life Sciences, Nussdorfer Laende 11, A-1190 Vienna, Austria.
Zinoecker
Irene
I
Marzban
Gorji
G
Katinger
Hermann
H
Laimer
Margit
M
D000485:Allergens / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D052179:Antigens, Plant; D029681:Arabidopsis Proteins / Q000235:genetics; D001483:Base Sequence; D015152:Blotting, Northern; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D027845:Malus / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques
D000485:Allergens; D052179:Antigens, Plant; D029681:Arabidopsis Proteins; D018744:DNA, Plant; C095551:MALD1 protein, Malus domestica; D010940:Plant Proteins; D012333:RNA, Messenger