Antifungal Pisum sativum Defensin 1 Interacts with Neurospora crassa Cyclin F Related to the Cell Cycle

详细信息    查看全文

• 作者：Denise S. Lobo ; Iuri B. Pereira ; Lucianne Fragel-Madeira ; Luciano N. Medeiros ; Luiz M. Cabral ; Jane Faria ; Maria Bellio ; Reinaldo C. Campos ; Rafael Linden ; Eleonora Kurtenbach
• 刊名：Biochemistry
• 出版年：2007
• 出版时间：January 30, 2007
• 年：2007
• 卷：46
• 期：4
• 页码：987 - 996
• 全文大小：445K
• 年卷期：v.46,no.4(January 30, 2007)
• ISSN：1520-4995

文摘

Plant defensins, components of the plant innate immune system, are cationic cysteine-richantifungal peptides. Evidence from the literature [Thevissen, K., et al. (2003) Peptides 24, 1705-1712]has demonstrated that patches of fungi membrane containing mannosyldiinositolphosphorylceramide andglucosylceramides are selective binding sites for the plant defensins isolated from Dahlia merckii andRaphanus sativus, respectively. Whether plant defensins interact directly or indirectly with fungusintracellular targets is unknown. To identify physical protein-protein interactions, a GAL4-based yeasttwo-hybrid system was performed using the antifungal plant peptide Pisum sativum defensin 1 (Psd1) asthe bait. Target proteins were screened within a Neurospora crassa cDNA library. Nine out of 11 two-hybrid candidates were nuclear proteins. One clone, detected with high frequency per screening, presentedsequence similarity to a cyclin-like protein, with F-box and WD-repeat domains, related to the cell cyclecontrol. GST pull-down assay corroborated in vitro this two-hybrid interaction. Fluorescence microscopyanalysis of FITC-conjugated Psd1 and DAPI-stained fungal nuclei showed in vivo the colocalization ofthe plant peptide Psd1 and the nucleus. Analysis of the DNA content of N. crassa conidia using flowcytometry suggested that Psd1 directed cell cycle impairment and caused conidia to undergo endoreduplication. The developing retina of neonatal rats was used as a model to observe the interkinetic nuclearmigration during proliferation of an organized tissue from the S toward the M phase of the cell cycle inthe presence of Psd1. The results demonstrated that the plant defensin Psd1 regulates interkinetic nuclearmigration in retinal neuroblasts.