The antifungal plant defensin AtPDF2.3 from Arabidopsis thaliana blocks potassium channels.
Sci Rep
; 6: 32121, 2016 08 30.
Article
en En
| MEDLINE
| ID: mdl-27573545
Scorpion toxins that block potassium channels and antimicrobial plant defensins share a common structural CSαß-motif. These toxins contain a toxin signature (K-C4-X-N) in their amino acid sequence, and based on in silico analysis of 18 plant defensin sequences, we noted the presence of a toxin signature (K-C5-R-G) in the amino acid sequence of the Arabidopsis thaliana defensin AtPDF2.3. We found that recombinant (r)AtPDF2.3 blocks Kv1.2 and Kv1.6 potassium channels, akin to the interaction between scorpion toxins and potassium channels. Moreover, rAtPDF2.3[G36N], a variant with a KCXN toxin signature (K-C5-R-N), is more potent in blocking Kv1.2 and Kv1.6 channels than rAtPDF2.3, whereas rAtPDF2.3[K33A], devoid of the toxin signature, is characterized by reduced Kv channel blocking activity. These findings highlight the importance of the KCXN scorpion toxin signature in the plant defensin sequence for blocking potassium channels. In addition, we found that rAtPDF2.3 inhibits the growth of Saccharomyces cerevisiae and that pathways regulating potassium transport and/or homeostasis confer tolerance of this yeast to rAtPDF2.3, indicating a role for potassium homeostasis in the fungal defence response towards rAtPDF2.3. Nevertheless, no differences in antifungal potency were observed between the rAtPDF2.3 variants, suggesting that antifungal activity and Kv channel inhibitory function are not linked.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas de Homeodominio
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Proteínas de Arabidopsis
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Bloqueadores de los Canales de Potasio
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Canales de Potasio de la Superfamilia Shaker
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Canal de Potasio Kv.1.2
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Antifúngicos
Límite:
Humans
Idioma:
En
Revista:
Sci Rep
Año:
2016
Tipo del documento:
Article
País de afiliación:
Bélgica
Pais de publicación:
Reino Unido