A novel aspartic proteinase is targeted to the secretory pathway and to the vacuole in the moss Physcomitrella patens.
Eur J Cell Biol
; 83(4): 145-52, 2004 May.
Article
em En
| MEDLINE
| ID: mdl-15260436
ABSTRACT
In seed plants aspartic proteases (APs) are known to reside in storage vacuoles. Targeting to this compartment is provoked by a secretory signal peptide and the plant-specific insert (PSI). In order to study secretory and vacuolar targeting in a seedless plant, the moss Physcomitrella patens, we isolated a cDNA encoding PpAP1, a novel aspartic proteinase. Sequence alignment with other members of the family of plant APs (EC 3.4.23) revealed a high overall identity and the Pfam motifs for aspartic proteinase and PSI were clearly recognised. In phylogenetic analysis PpAP1 was placed at a very basal position outside of the bigger clusters. Protoplasts transiently expressing the PpAP1 signal peptide fused to GFP showed fluorescence in a well-developed ER-Golgi network. A C-terminal fusion of GFP to the entire PpAP1 protein showed vacuolar fluorescence in transiently transfected protoplasts. Therefore, the vacuole is apparently the in-vivo target for PpAP1. In this study the three-dimensional peculiarity of the endomembrane continuum of ER and Golgi was visualised in a seedless plant for the first time. Above all the functionality of the secretory and the vacuolar targeting signals make them become useful tools for biotechnological approaches.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vacúolos
/
Ácido Aspártico Endopeptidases
/
Bryopsida
/
Vesículas Secretórias
Idioma:
En
Revista:
Eur J Cell Biol
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Alemanha