| RRC ID |
54615
|
| 著者 |
Porodko A, Cirnski A, Petrov D, Raab T, Paireder M, Mayer B, Maresch D, Nika L, Biniossek ML, Gallois P, Schilling O, Oostenbrink C, Novinec M, Mach L.
|
| タイトル |
The two cathepsin B-like proteases of Arabidopsis thaliana are closely related enzymes with discrete endopeptidase and carboxydipeptidase activities.
|
| ジャーナル |
Biol Chem
|
| Abstract |
The genome of the model plant Arabidopsis thaliana encodes three paralogues of the papain-like cysteine proteinase cathepsin B (AtCathB1, AtCathB2 and AtCathB3), whose individual functions are still largely unknown. Here we show that a mutated splice site causes severe truncations of the AtCathB1 polypeptide, rendering it catalytically incompetent. By contrast, AtCathB2 and AtCathB3 are effective proteases which display comparable hydrolytic properties and share most of their substrate specificities. Site-directed mutagenesis experiments demonstrated that a single amino acid substitution (Gly336→Glu) is sufficient to confer AtCathB2 with the capacity to tolerate arginine in its specificity-determining S2 subsite, which is otherwise a hallmark of AtCathB3-mediated cleavages. A degradomics approach utilizing proteome-derived peptide libraries revealed that both enzymes are capable of acting as endopeptidases and exopeptidases, releasing dipeptides from the C-termini of substrates. Mutation of the carboxydipeptidase determinant His207 also affected the activity of AtCathB2 towards non-exopeptidase substrates, highlighting mechanistic differences between plant and human cathepsin B. This was also noted in molecular modeling studies which indicate that the occluding loop defining the dual enzymatic character of cathepsin B does not obstruct the active-site cleft of AtCathB2 to the same extent as in its mammalian orthologues.
|
| 巻・号 |
399(10)
|
| ページ |
1223-1235
|
| 公開日 |
2018-9-25
|
| DOI |
10.1515/hsz-2018-0186
|
| PII |
/j/bchm.just-accepted/hsz-2018-0186/hsz-2018-0186.xml
|
| PMID |
29924726
|
| MeSH |
Animals
Arabidopsis / enzymology*
Carboxypeptidases / chemistry
Carboxypeptidases / genetics
Carboxypeptidases / metabolism*
Cathepsin B / chemistry
Cathepsin B / genetics
Cathepsin B / metabolism*
Cloning, Molecular
Endopeptidases / chemistry
Endopeptidases / genetics
Endopeptidases / metabolism*
Models, Molecular
Mutagenesis, Site-Directed
Plant Leaves / enzymology
Real-Time Polymerase Chain Reaction
Spodoptera / cytology
Spodoptera / genetics
|
| IF |
3.014
|
| 引用数 |
3
|
| リソース情報 |
| シロイヌナズナ / 植物培養細胞・遺伝子 |
pda02452
pda06461 |
