OsKinesin-13A Is an Active Microtubule Depolymerase Involved in Glume Length Regulation via Affecting Cell Elongation

Abstract In the fission yeast Schizosaccharomyces pombe, as in other eukaryotic cells, Cdc2/cyclin B complex is the key regulator of mitosis. Perhaps the most important regulation of Cdc2 is the inhibitory phosphorylation of tyrosine-15 that is catalyzed by Wee1 and Mik1. Cdc25 and Pyp3 phosphatases dephosphorylate tyrosine-15 and activate Cdc2. To isolate novel activators of Cdc2 kinase, we screened synthetic lethal mutants in a cdc25-22 background at the permissive temperature (25°). One of the genes, slm9, encodes a novel protein of 807 amino acids. Slm9 is most similar to Hir2, the histone gene regulator in budding yeast. Slm9 protein level is constant and Slm9 is localized to the nucleus throughout the cell cycle. The slm9 disruptant is delayed at the G2-M transition as indicated by cell elongation and analysis of DNA content. Inactivation of Wee1 fully suppressed the cell elongation phenotype caused by the slm9 mutation. The slm9 mutant is defective in recovery from G1 arrest after nitrogen starvation. The slm9 mutant is also UV sensitive, showing a defect in recovery from the cell cycle arrest after UV irradiation.

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Rif1 regulates telomere length through conserved HEAT repeats

Nucleic Acids Research ◽

10.1093/nar/gkab206 ◽

2021 ◽

Vol 49 (7) ◽

pp. 3967-3980

Author(s):

Calla B Shubin ◽

Rini Mayangsari ◽

Ariel D Swett ◽

Carol W Greider

Keyword(s):

Dna Binding ◽

Telomere Length ◽

Functional Role ◽

Conserved Residues ◽

Binding Interface ◽

Binding Function ◽

Length Regulation ◽

Telomere Length Regulation ◽

Telomere Regulation ◽

Conserved Amino Acids

AbstractIn budding yeast, Rif1 negatively regulates telomere length, but the mechanism of this regulation has remained elusive. Previous work identified several functional domains of Rif1, but none of these has been shown to mediate telomere length. To define Rif1 domains responsible for telomere regulation, we localized truncations of Rif1 to a single specific telomere and measured telomere length of that telomere compared to bulk telomeres. We found that a domain in the N-terminus containing HEAT repeats, Rif1177–996, was sufficient for length regulation when tethered to the telomere. Charged residues in this region were previously proposed to mediate DNA binding. We found that mutation of these residues disrupted telomere length regulation even when Rif1 was tethered to the telomere. Mutation of other conserved residues in this region, which were not predicted to interact with DNA, also disrupted telomere length maintenance, while mutation of conserved residues distal to this region did not. Our data suggest that conserved amino acids in the region from 436 to 577 play a functional role in telomere length regulation, which is separate from their proposed DNA binding function. We propose that the Rif1 HEAT repeats region represents a protein-protein binding interface that mediates telomere length regulation.

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Effect of O-Antigen Chain Length Regulation on the Immunogenicity of Shigella and Salmonella Generalized Modules for Membrane Antigens (GMMA)

International Journal of Molecular Sciences ◽

10.3390/ijms22031309 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1309

Author(s):

Gianmarco Gasperini ◽

Maria Michelina Raso ◽

Vanessa Arato ◽

Maria Grazia Aruta ◽

Paola Cescutti ◽

...

Keyword(s):

Immune Response ◽

Structural Characteristics ◽

Antigen Delivery ◽

Critical Quality Attributes ◽

O Antigen ◽

Alternative Approach ◽

Length Regulation ◽

Membrane Antigens ◽

Glycoconjugate Vaccines ◽

Work Supports

Recently, generalized modules for membrane antigens (GMMA) technology has been proposed as an alternative approach to traditional glycoconjugate vaccines for O-antigen delivery. Saccharide length is a well-known parameter that can impact the immune response induced by glycoconjugates both in terms of magnitude and quality. However, the criticality of O-antigen length on the immune response induced by GMMA-based vaccines has not been fully elucidated. Here, Shigella and Salmonella GMMA-producing strains were further mutated in order to display homogeneous polysaccharide populations of different sizes on a GMMA surface. Resulting GMMA were compared in mice immunization studies. Athymic nude mice were also used to investigate the involvement of T-cells in the immune response elicited. In contrast with what has been reported for traditional glycoconjugate vaccines and independent of the pathogen and the sugar structural characteristics, O-antigen length did not result in being a critical parameter for GMMA immunogenicity. This work supports the identification of critical quality attributes to optimize GMMA vaccine design and improve vaccine efficacy and gives insights on the nature of the immune response induced by GMMA.

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Vacuolar occupancy is crucial for cell elongation and growth regardless of the underlying mechanism

Plant Signaling & Behavior ◽

10.1080/15592324.2021.1922796 ◽

2021 ◽

pp. 1922796

Author(s):

Sabrina Kaiser ◽

Sophie Eisele ◽

David Scheuring

Keyword(s):

Cell Elongation ◽

Underlying Mechanism

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Transcriptome and metabolome profiling provide insights into molecular mechanism of pseudostem elongation in banana

BMC Plant Biology ◽

10.1186/s12870-021-02899-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Guiming Deng ◽

Fangcheng Bi ◽

Jing Liu ◽

Weidi He ◽

Chunyu Li ◽

...

Keyword(s):

Cell Wall ◽

Cell Elongation ◽

Molecular Mechanisms ◽

Specific Gene ◽

Wild Type ◽

Banana Plant ◽

Cell Wall Modification ◽

Dwarf Cultivar ◽

Important Trait ◽

Metabolome Profiling

AbstractBackgroundBanana plant height is an important trait for horticultural practices and semi-dwarf cultivars show better resistance to damages by wind and rain. However, the molecular mechanisms controlling the pseudostem height remain poorly understood. Herein, we studied the molecular changes in the pseudostem of a semi-dwarf banana mutant Aifen No. 1 (Musaspp. Pisang Awak sub-group ABB) as compared to its wild-type dwarf cultivar using a combined transcriptome and metabolome approach.ResultsA total of 127 differentially expressed genes and 48 differentially accumulated metabolites were detected between the mutant and its wild type. Metabolites belonging to amino acid and its derivatives, flavonoids, lignans, coumarins, organic acids, and phenolic acids were up-regulated in the mutant. The transcriptome analysis showed the differential regulation of genes related to the gibberellin pathway, auxin transport, cell elongation, and cell wall modification. Based on the regulation of gibberellin and associated pathway-related genes, we discussed the involvement of gibberellins in pseudostem elongation in the mutant banana. Genes and metabolites associated with cell wall were explored and their involvement in cell extension is discussed.ConclusionsThe results suggest that gibberellins and associated pathways are possibly developing the observed semi-dwarf pseudostem phenotype together with cell elongation and cell wall modification. The findings increase the understanding of the mechanisms underlying banana stem height and provide new clues for further dissection of specific gene functions.

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