1P006 Structural studies of RNA-binding protein Nrd1, a fission yeast MAPK target RNA binding protein(01A. Protein:Structure,Poster)

Cells form a bipolar spindle during mitosis to ensure accurate chromosome segregation. Proper spindle architecture is established by a set of kinesin motors and microtubule-associated proteins. In most eukaryotes, kinesin-5 motors are essential for this process, and genetic or chemical inhibition of their activity leads to the emergence of monopolar spindles and cell death. However, these deficiencies can be rescued by simultaneous inactivation of kinesin-14 motors, as they counteract kinesin-5. We conducted detailed genetic analyses in fission yeast to understand the mechanisms driving spindle assembly in the absence of kinesin-5. Here we show that deletion of the nrp1 gene, which encodes a putative RNA-binding protein with unknown function, can rescue temperature sensitivity caused by cut7-22, a fission yeast kinesin-5 mutant. Interestingly, kinesin-14/Klp2 levels on the spindles in the cut7 mutants were significantly reduced by the nrp1 deletion, although the total levels of Klp2 and the stability of spindle microtubules remained unaffected. Moreover, RNA-binding motifs of Nrp1 are essential for its cytoplasmic localization and function. We have also found that a portion of Nrp1 is spatially and functionally sequestered by chaperone-based protein aggregates upon mild heat stress and limits cell division at high temperatures. We propose that Nrp1 might be involved in post-transcriptional regulation through its RNA-binding ability to promote the loading of Klp2 on the spindle microtubules.

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Phosphorylation of RNA-binding protein controls cell cycle switch from mitotic to meiotic in fission yeast

Nature ◽

10.1038/386187a0 ◽

1997 ◽

Vol 386 (6621) ◽

pp. 187-190 ◽

Cited By ~ 114

Author(s):

Yoshinori Watanabe ◽

Satoko Shinozaki-Yabana ◽

Yuji Chikashige ◽

Yasushi Hiraoka ◽

Masayuki Yamamoto

Keyword(s):

Cell Cycle ◽

Fission Yeast ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein

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The Fission Yeast RNA Binding Protein Mmi1 Regulates Meiotic Genes by Controlling Intron Specific Splicing and Polyadenylation Coupled RNA Turnover

PLoS ONE ◽

10.1371/journal.pone.0026804 ◽

2011 ◽

Vol 6 (10) ◽

pp. e26804 ◽

Cited By ~ 50

Author(s):

Huei-Mei Chen ◽

Bruce Futcher ◽

Janet Leatherwood

Keyword(s):

Fission Yeast ◽

Rna Binding ◽

Binding Protein ◽

Rna Binding Protein ◽

Rna Turnover

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Combinatorial recognition of clustered RNA elements by a multidomain RNA-binding protein, IMP3

10.1101/398008 ◽

2018 ◽

Cited By ~ 1

Author(s):

Tim Schneider ◽

Lee-Hsueh Hung ◽

Masood Aziz ◽

Anna Wilmen ◽

Stephanie Thaum ◽

...

Keyword(s):

Binding Proteins ◽

Rna Binding ◽

Rna Binding Proteins ◽

Binding Protein ◽

Rna Binding Protein ◽

Binding Domains ◽

Systematic Strategy ◽

Rna Elements ◽

Target Rna

AbstractHow multidomain RNA-binding proteins recognize their specific target sequences, based on a combinatorial code, represents a fundamental unsolved question and has not been studied systematically so far. Here we focus on a prototypical multidomain RNA-binding protein, IMP3 (also called IGF2BP3), which contains six RNA-binding domains (RBDs): four KH and two RRM domains. We have established an integrative systematic strategy, combining single-domain-resolved SELEX-seq, motif-spacing analyses, in vivo iCLIP, functional validation assays, and structural biology. This approach identifies the RNA-binding specificity and RNP topology of IMP3, involving all six RBDs and a cluster of up to five distinct and appropriately spaced CA-rich and GGC-core RNA elements, covering a >100 nucleotide-long target RNA region. Our generally applicable approach explains both specificity and flexibility of IMP3-RNA recognition, providing a paradigm for the function of multivalent interactions with multidomain RNA-binding proteins in gene regulation.

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Role of the RNA-binding Protein Nrd1 and Pmk1 Mitogen-activated Protein Kinase in the Regulation of Myosin mRNA Stability in Fission Yeast

Molecular Biology of the Cell ◽

10.1091/mbc.e08-09-0893 ◽

2009 ◽

Vol 20 (9) ◽

pp. 2473-2485 ◽

Cited By ~ 25

Author(s):

Ryosuke Satoh ◽

Takahiro Morita ◽

Hirofumi Takada ◽

Ayako Kita ◽

Shunji Ishiwata ◽

...

Keyword(s):

Protein Kinase ◽

Fission Yeast ◽

Mrna Stability ◽

Rna Binding ◽

Binding Protein ◽

Myosin Ii ◽

Rna Binding Protein ◽

Mapk Signaling ◽

Mitogen Activated Protein Kinase ◽

Mitogen Activated Protein

Myosin II is an essential component of the actomyosin contractile ring and plays a crucial role in cytokinesis by generating the forces necessary for contraction of the actomyosin ring. Cdc4 is an essential myosin II light chain in fission yeast and is required for cytokinesis. In various eukaryotes, the phosphorylation of myosin is well documented as a primary means of activating myosin II, but little is known about the regulatory mechanisms of Cdc4. Here, we isolated Nrd1, an RNA-binding protein with RNA-recognition motifs, as a multicopy suppressor of cdc4 mutants. Notably, we demonstrated that Nrd1 binds and stabilizes Cdc4 mRNA, thereby suppressing the cytokinesis defects of the cdc4 mutants. Importantly, Pmk1 mitogen-activated protein kinase (MAPK) directly phosphorylates Nrd1, thereby negatively regulating the binding activity of Nrd1 to Cdc4 mRNA. Consistently, the inactivation of Pmk1 MAPK signaling, as well as Nrd1 overexpression, stabilized the Cdc4 mRNA level, thereby suppressing the cytokinesis defects associated with the cdc4 mutants. In addition, we demonstrated the cell cycle–dependent regulation of Pmk1/Nrd1 signaling. Together, our results indicate that Nrd1 plays a role in the regulation of Cdc4 mRNA stability; moreover, our study is the first to demonstrate the posttranscriptional regulation of myosin expression by MAPK signaling.

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