Molecular cloning and characterization of a cDNA encoding a novel apoplastic protein preferentially expressed in a shikonin-producing callus strain of Lithospermum erythrorhizon.
A cDNA (LEPS-2) encoding a novel cell wall protein was cloned from shikonin-producing callus tissues of Lithospermum erythrorhizon by differential display between a shikonin-producing culture strain and a non-producing strain. The LEPS-2 cDNA encoded a polypeptide of 184 amino acids. The deduced amino acid sequence exhibited no significant homology with known proteins. Expression of LEPS-2 gene as well as accumulation of LEPS-2 protein was highly correlated with shikonin production in L. erythrorhizon cells in culture. In the intact plant, expression of LEPS-2 was detected only in the roots where shikonin pigments accumulated. Cell fractionation experiments and immunocytochemical analysis showed that the protein was localized in the apoplast fraction of the cell walls. The shikonin pigments were also stored on the cell walls as oil droplets. These results indicate that expression of the LEPS-2 is closely linked with shikonin biosynthesis and the LEPS-2 protein may be involved in the intra-cell wall trapping of shikonin pigments.
Graduate School of Pharmaceutical Sciences, Nagoya City University, Mizuho-ku, Nagoya, 467-8603 Japan.
Yoshimi
Y
Yamamura
F Pinar
FP
Sahin
Akito
A
Nagatsu
Hajime
H
Mizukami
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D046508:Culture Techniques; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004798:Enzymes / Q000235:genetics / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D029684:Lithospermum / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009285:Naphthoquinones / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D020005:Propanols / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity
D018076:DNA, Complementary; D004798:Enzymes; D009285:Naphthoquinones; D010940:Plant Proteins; D020005:Propanols; D012333:RNA, Messenger; C439395:1-phenylpropanol; C016101:shikonin