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Zhang S, Lin C, Zhou T, Zhang LH, Deng YZ. Karyopherin MoKap119-mediated nuclear import of cyclin-dependent kinase regulator MoCks1 is essential for Magnaporthe oryzae pathogenicity. Cell Microbiol 2019; 22:e13114. [PMID: 31487436 DOI: 10.1111/cmi.13114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/21/2019] [Accepted: 09/02/2019] [Indexed: 12/29/2022]
Abstract
Nuclear import of proteins relies on nuclear import receptors called importins/karyopherins (Kaps), whose functions were reported in yeasts, fungi, plants, and animal cells, including cell cycle control, morphogenesis, stress sensing/response, and also fungal pathogenecity. However, limited is known about the physiological function and regulatory mechanism of protein import in the rice-blast fungus Magnaporthe oryzae. Here, we identified an ortholog of β-importin in M. oryzae encoded by an ortholog of KAP119 gene. Functional characterisation of this gene via reverse genetics revealed that it is required for vegetative growth, conidiation, melanin pigmentation, and pathogenicity of M. oryzae. The mokap119Δ mutant was also defective in formation of appressorium-like structure from hyphal tips. By affinity assay and liquid chromatography-tandem mass spectrometry, we identified potential MoKap119-interacting proteins and further verified that MoKap119 interacts with the cyclin-dependent kinase subunit MoCks1 and mediates its nuclear import. Transcriptional profiling indicated that MoKap119 may regulate transcription of infection-related genes via MoCks1 regulation of MoSom1. Overall, our findings provide a novel insight into the regulatory mechanism of M. oryzae pathogenesis likely by MoKap119-mediated nuclear import of the cyclin-dependent kinase subunit MoCks1.
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Affiliation(s)
- Shulin Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China.,Integrative Microbiology Research Centre/Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Chaoxiang Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China.,Integrative Microbiology Research Centre/Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Tian Zhou
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China.,Integrative Microbiology Research Centre/Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Lian-Hui Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China.,Integrative Microbiology Research Centre/Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Yi Zhen Deng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, China.,Integrative Microbiology Research Centre/Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
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Quilis I, Taberner FJ, Martínez-Garay CA, Alepuz P, Igual JC. Karyopherin Msn5 is involved in a novel mechanism controlling the cellular level of cell cycle regulators Cln2 and Swi5. Cell Cycle 2019; 18:580-595. [PMID: 30739521 PMCID: PMC6464581 DOI: 10.1080/15384101.2019.1578148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The yeast β-karyopherin Msn5 controls the SBF cell-cycle transcription factor, responsible for the periodic expression of CLN2 cyclin gene at G1/S, and the nuclear export of Cln2 protein. Here we show that Msn5 regulates Cln2 by an additional mechanism. Inactivation of Msn5 causes a severe reduction in the cellular content of Cln2. This occurs by a post-transcriptional mechanism, since CLN2 mRNA level is not importantly affected in asynchronous cultures. Cln2 stability is not significantly altered in msn5 cells and inactivation of Msn5 causes a reduction in protein level even when Cln2 is stabilized. Therefore, the reduced amount of Cln2 in msn5 cells is mainly due not to a higher rate of protein degradation but to a defect in Cln2 synthesis. In fact, analysis of polysome profiles indicated that Msn5 inactivation causes a shift of CLN2 and SWI5 mRNAs from heavy-polysomal to light-polysomal and non-polysomal fractions, supporting a defect in Cln2 and Swi5 protein synthesis in the msn5 mutant. The analysis of truncated versions of Cln2 and of chimeric cyclins combining distinct domains from Cln2 and the related Cln1 cyclin identified an internal region in Cln2 from 181 to 225 residues that when fused to GFP is able to confer Msn5-dependent regulation of protein cellular content. Finally, we showed that a high level of Cln2 is toxic in the absence of Msn5. In summary, we described that Msn5 is required for the proper protein synthesis of specific proteins, introducing a new level of control of cell cycle regulators.
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Affiliation(s)
- Inma Quilis
- a Departament de Bioquímica i Biologia Molecular , Universitat de València , Valencia , Spain.,b Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED) , Universitat de València , Valencia , Spain
| | - Francisco J Taberner
- a Departament de Bioquímica i Biologia Molecular , Universitat de València , Valencia , Spain.,b Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED) , Universitat de València , Valencia , Spain
| | - Carlos A Martínez-Garay
- a Departament de Bioquímica i Biologia Molecular , Universitat de València , Valencia , Spain.,b Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED) , Universitat de València , Valencia , Spain
| | - Paula Alepuz
- a Departament de Bioquímica i Biologia Molecular , Universitat de València , Valencia , Spain.,b Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED) , Universitat de València , Valencia , Spain
| | - J Carlos Igual
- a Departament de Bioquímica i Biologia Molecular , Universitat de València , Valencia , Spain.,b Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED) , Universitat de València , Valencia , Spain
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Quilis I, Igual JC. Molecular basis of the functional distinction between Cln1 and Cln2 cyclins. Cell Cycle 2012; 11:3117-31. [PMID: 22889732 DOI: 10.4161/cc.21505] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Cln1 and Cln2 are very similar but not identical cyclins. In this work, we tried to describe the molecular basis of the functional distinction between Cln1 and Cln2. We constructed chimeric cyclins containing different fragments of Cln1 and Cln2 and performed several functional analysis that make it possible to distinguish between Cln1 or Cln2. We identified that region between amino acids 225 and 299 of Cln2 is not only necessary but also sufficient to confer Cln2 specific functionality compared with Cln1. We also studied Cln1 and Cln2 subcellular localization identifying additional differences between them. Both cyclins are distributed between the nucleus and the cytoplasm, but Cln1 shows stronger nuclear accumulation. Nuclear import of both cyclins is mediated by the classical nuclear import pathway and by sequences in the N-terminal end of the proteins. For Cln2, but not for Cln1, a nuclear export mechanism mediated by karyopherin Msn5 has been identified. Strikingly, Cln2 export depends on a Msn5-dependent NES between amino acids 225 and 299. In fact, the introduction of this region confers to Cln1 an export mechanism dependent on Msn5; importantly, this causes the gain of Cln2-specific cytosolic functions and the impairment of nuclear function. In short, a region from Cln2 controlling an Msn5-dependent nuclear export mechanism confers a specific functionality to Cln2 compared with Cln1.
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Affiliation(s)
- Inma Quilis
- Departament de Bioquímica i Biologia Molecular, Universitat de València, Burjassot, Spain
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