Untitled

Abstract

An abundant 17 kDa protein which was isolated and characterized from 10-day old healthy root tissue of white lupin (Lupinus albus) proved to have a high sequence similarity to pathogenesis-related proteins found in other species. Subsequently, a corresponding clone (LaPR-10) was identified in a cDNA library prepared from the same tissue that exhibited a high amino acid sequence similarity to a number of the PR-10 family proteins. The clone contains an open reading frame encoding a polypeptide of 158 amino acids, with a predicted molecular mass of 16,905 Da and an isoelectric point of 4.66. Southern blot analysis indicates that LaPR-10 is likely a single-copy gene, or a member of a small gene family. The clone was expressed in Escherichia coli, and its protein product was purified to near homogeneity. Both the native and the recombinant proteins were immunorecognized by antibodies raised against pea PR-10 proteins, and exhibited a ribonucleolytic activity against several RNA preparations, including lupin root total RNA. Characterization of its enzymatic properties indicates that the LaPR-10 protein belongs to the class II ribonucleases. We present evidence that the white lupin 17 kDa protein is constitutively expressed during all stages of root development and, to a lesser extent, in other plant parts. In addition, we demonstrate the presence, in the LaPR-10 amino acid sequence, of a number of motifs that are common to most PR-10 proteins, as well as a RGD motif that is shared only with the alfalfa SRG1 sequence.

Molecular Characteristics and Biochemical Functions of VpPR10s from Vitis pseudoreticulata Associated with Biotic and Abiotic Stresses

“…It has been reported that the P-loop domain and Bet v 1 motif are contained in the amino acid sequence of PR10 proteins in Lupinus albus (LaPR10) [40], Asiatic cotton (GaPR10) [36], peanuts [37] and pepper [42]. The relationships between the two conservative domains and nuclease activity were further confirmed in our experiment.…”

“…They also showed a relationship between the antifungal activity of PR10 protein and its RNase activity in vitro [37]. Moreover, it has been shown that white lupin LaPR10 [40], cotton GaPR10 [36] and chili PR10 proteins [41,42] all have ribonuclease activity and antifungal activity. Besides these plants, PR10 proteins in rice [43] and pea [44] have also been confirmed as having nuclease activity in vitro .…”

The Major Birch Allergen, Bet v 1, Shows Affinity for a Broad Spectrum of Physiological Ligands

“…Several of the PR-10 proteins have been proposed to possess RNase activity (22)(23)(24)(25), which may constitute a common trait of this protein family (50). The present study clearly demonstrates that Bet v 1 is capable of binding several types of ligands, most of which bind in the cavity suggesting a transport or storage function of Bet v 1, a role that is difficult to reconcile with RNase activity.…”

“…Very recently, the major allergen from cherry, Pru av 1, whose backbone folding pattern is very similar to that of Bet v 1, was reported to bind the phytosteroid homocastasterone (21). Furthermore, PR-10 members from ginseng (22) and white lupin (23) as well as Bet v 1 (24,25) have been reported to show RNase activity. It thus appears that PR-10 proteins display enzymatic activity as well as ligand binding activity, which is also reflected in the classification of the START domain superfamily, including both START domain proteins and PR-10 proteins among others (26).…”

Transcriptome analysis of a bacterially induced basal and hypersensitive response of Medicago truncatula

“…The cytosol localized PR-10 proteins are induced by phytopathogens and environmental stresses (Breda et al 1996;Liu and Ekramoddoullah 2006). In addition to their ribonuclease activity (Bantignies et al 2000), the PR-10 and PR-10-related proteins can bind plant hormones, such as brassinosteroids (Marković-Housley et al 2003) and cytokinins (Koistinen et al 2005). Both hormones can induce or influence disease resistance (Nakashita et al 2003;Carimi et al 2003;Novacky 1972).…”