BAF-1 mobility is regulated by environmental stresses

Barrier to autointegration factor (BAF) is an essential component of the nuclear lamina that binds lamins, LEM-domain proteins, histones, and DNA. Under normal conditions, BAF protein is highly mobile when assayed by fluorescence recovery after photobleaching and fluorescence loss in photobleaching. We report that Caenorhabditis elegans BAF-1 mobility is regulated by caloric restriction, food deprivation, and heat shock. This was not a general response of chromatin-associated proteins, as food deprivation did not affect the mobility of heterochromatin protein HPL-1 or HPL-2. Heat shock also increased the level of BAF-1 Ser-4 phosphorylation. By using missense mutations that affect BAF-1 binding to different partners we find that, overall, the ability of BAF-1 mutants to be immobilized by heat shock in intestinal cells correlated with normal or increased affinity for emerin in vitro. These results show BAF-1 localization and mobility at the nuclear lamina are regulated by stress and unexpectedly reveal BAF-1 immobilization as a specific response to caloric restriction in C. elegans intestinal cells.

Download Full-text

The noncanonical small heat shock protein HSP-17 from Caenorhabditis elegans is a selective protein aggregase

Journal of Biological Chemistry ◽

10.1074/jbc.ra119.011185 ◽

2020 ◽

Vol 295 (10) ◽

pp. 3064-3079 ◽

Cited By ~ 1

Author(s):

Manuel Iburg ◽

Dmytro Puchkov ◽

Irving U. Rosas-Brugada ◽

Linda Bergemann ◽

Ulrike Rieprecht ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Heat Shock ◽

Small Heat Shock Protein ◽

Independent Manner ◽

C Elegans ◽

Higher Eukaryotes ◽

Prolonged Heat ◽

Shock Proteins ◽

Excretory Organs

Small heat shock proteins (sHsps) are conserved, ubiquitous members of the proteostasis network. Canonically, they act as “holdases” and buffer unfolded or misfolded proteins against aggregation in an ATP-independent manner. Whereas bacteria and yeast each have only two sHsps in their genomes, this number is higher in metazoan genomes, suggesting a spatiotemporal and functional specialization in higher eukaryotes. Here, using recombinantly expressed and purified proteins, static light-scattering analysis, and disaggregation assays, we report that the noncanonical sHsp HSP-17 of Caenorhabditis elegans facilitates aggregation of model substrates, such as malate dehydrogenase (MDH), and inhibits disaggregation of luciferase in vitro. Experiments with fluorescently tagged HSP-17 under the control of its endogenous promoter revealed that HSP-17 is expressed in the digestive and excretory organs, where its overexpression promotes the aggregation of polyQ proteins and of the endogenous kinase KIN-19. Systemic depletion of hsp-17 shortens C. elegans lifespan and severely reduces fecundity and survival upon prolonged heat stress. HSP-17 is an abundant protein exhibiting opposing chaperone activities on different substrates, indicating that it is a selective protein aggregase with physiological roles in development, digestion, and osmoregulation.

Download Full-text

A laminopathic mutation disrupting lamin filament assembly causes disease-like phenotypes in Caenorhabditis elegans

Molecular Biology of the Cell ◽

10.1091/mbc.e11-01-0064 ◽

2011 ◽

Vol 22 (15) ◽

pp. 2716-2728 ◽

Cited By ~ 32

Author(s):

Erin M. Bank ◽

Kfir Ben-Harush ◽

Naama Wiesel-Motiuk ◽

Rachel Barkan ◽

Naomi Feinstein ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Fluorescent Protein ◽

Electron Tomography ◽

Nuclear Periphery ◽

Nuclear Lamina ◽

C Elegans ◽

Filament Assembly ◽

Filament Structure ◽

Green Fluorescent

Mutations in the human LMNA gene underlie many laminopathic diseases, including Emery-Dreifuss muscular dystrophy (EDMD); however, a mechanistic link between the effect of mutations on lamin filament assembly and disease phenotypes has not been established. We studied the ΔK46 Caenorhabditis elegans lamin mutant, corresponding to EDMD-linked ΔK32 in human lamins A and C. Cryo-electron tomography of lamin ΔK46 filaments in vitro revealed alterations in the lateral assembly of dimeric head-to-tail polymers, which causes abnormal organization of tetrameric protofilaments. Green fluorescent protein (GFP):ΔK46 lamin expressed in C. elegans was found in nuclear aggregates in postembryonic stages along with LEM-2. GFP:ΔK46 also caused mislocalization of emerin away from the nuclear periphery, consistent with a decreased ability of purified emerin to associate with lamin ΔK46 filaments in vitro. GFP:ΔK46 animals had motility defects and muscle structure abnormalities. These results show that changes in lamin filament structure can translate into disease-like phenotypes via altering the localization of nuclear lamina proteins, and suggest a model for how the ΔK32 lamin mutation may cause EDMD in humans.

Download Full-text

Caloric restriction induces heat shock response and inhibits B16F10 cell tumorigenesis both in vitro and in vivo

Aging ◽

10.18632/aging.100732 ◽

2015 ◽

Vol 7 (4) ◽

pp. 233-240 ◽

Cited By ~ 3

Author(s):

Marta G. Novelle ◽

Ashley Davis ◽

Nathan L. Price ◽

Ahmed Ali ◽

Stefanie Fürer-Galvan ◽

...

Keyword(s):

Heat Shock ◽

Caloric Restriction ◽

Heat Shock Response ◽

B16f10 Cell ◽

Shock Response

Download Full-text

unc-83encodes a novel component of the nuclear envelope and is essential for proper nuclear migration

Development ◽

10.1242/dev.128.24.5039 ◽

2001 ◽

Vol 128 (24) ◽

pp. 5039-5050 ◽

Cited By ~ 3

Author(s):

Daniel A. Starr ◽

Greg J. Hermann ◽

Christian J. Malone ◽

William Fixsen ◽

James R. Priess ◽

...

Keyword(s):

Nuclear Envelope ◽

Essential Role ◽

Transmembrane Protein ◽

Nuclear Lamina ◽

Nuclear Migration ◽

C Elegans ◽

Specific Manner ◽

Sun Domain ◽

P Cells

Nuclear migration plays an essential role in the growth and development of a wide variety of eukaryotes. Mutations in unc-84, which encodes a conserved component of the nuclear envelope, have been shown to disrupt nuclear migration in two C. elegans tissues. We show that mutations in unc-83 disrupt nuclear migration in a similar manner in migrating P cells, hyp7 precursors and the intestinal primordium, but have no obvious defects in the association of centrosomes with nuclei or the structure of the nuclear lamina of migrating nuclei. We also show that unc-83 encodes a novel transmembrane protein. We identified three unc-83 transcripts that are expressed in a tissue-specific manner. Antibodies against UNC-83 co-localized to the nuclear envelope with lamin and UNC-84. Unlike UNC-84, UNC-83 localized to only specific nuclei, many of which were migratory. UNC-83 failed to localize to the nuclear envelope in unc-84 mutants with lesions in the conserved SUN domain of UNC-84, and UNC-83 interacted with the SUN domain of UNC-84 in vitro, suggesting that these two proteins function together during nuclear migration. We favor a model in which UNC-84 directly recruits UNC-83 to the nuclear envelope where they help transfer force between the cytoskeleton and the nucleus.

Download Full-text

Enterococcus faeciumNCIMB 10415 Modulates Epithelial Integrity, Heat Shock Protein, and Proinflammatory Cytokine Response in Intestinal Cells

Mediators of Inflammation ◽

10.1155/2015/304149 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 23

Author(s):

Shanti Klingspor ◽

Angelika Bondzio ◽

Holger Martens ◽

Jörg R. Aschenbach ◽

Katharina Bratz ◽

...

Keyword(s):

Heat Shock ◽

Heat Shock Protein ◽

Gastrointestinal Diseases ◽

Intestinal Cells ◽

Intestinal Epithelial ◽

E Coli ◽

Positive Effects ◽

Diarrhea Incidence ◽

Mrna And Protein Expression

Probiotics have shown positive effects on gastrointestinal diseases; they have barrier-modulating effects and change the inflammatory response towards pathogens in studiesin vitro. The aim of this investigation has been to examine the response of intestinal epithelial cells toEnterococcus faeciumNCIMB 10415 (E. faecium), a probiotic positively affecting diarrhea incidence in piglets, and two pathogenicEscherichia coli(E. coli) strains, with specific focus on the probiotic modulation of the response to the pathogenic challenge. Porcine (IPEC-J2) and human (Caco-2) intestinal cells were incubated without bacteria (control), withE. faecium, with enteropathogenic (EPEC) or enterotoxigenicE. coli(ETEC) each alone or in combination withE. faecium. The ETEC strain decreased transepithelial resistance (TER) and increased IL-8 mRNA and protein expression in both cell lines compared with control cells, an effect that could be prevented by pre- and coincubation withE. faecium. Similar effects were observed for the increased expression of heat shock protein 70 in Caco-2 cells. When the cells were challenged by the EPEC strain, no such pattern of changes could be observed. The reduced decrease in TER and the reduction of the proinflammatory and stress response of enterocytes following pathogenic challenge indicate the protective effect of the probiotic.

Download Full-text

Host CDK-1 and formin mediate microvillar effacement induced by enterohemorrhagic Escherichia coli

Nature Communications ◽

10.1038/s41467-020-20355-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Cheng-Rung Huang ◽

Cheng-Ju Kuo ◽

Chih-Wen Huang ◽

Yu-Ting Chen ◽

Bang-Yu Liu ◽

...

Keyword(s):

Escherichia Coli ◽

Enterohemorrhagic Escherichia Coli ◽

Intestinal Cell ◽

Intestinal Cells ◽

Cyclin Dependent Kinase ◽

C Elegans ◽

Mitotic Cyclin ◽

Human Intestinal Cells

AbstractEnterohemorrhagic Escherichia coli (EHEC) induces changes to the intestinal cell cytoskeleton and formation of attaching and effacing lesions, characterized by the effacement of microvilli and then formation of actin pedestals to which the bacteria are tightly attached. Here, we use a Caenorhabditis elegans model of EHEC infection to show that microvillar effacement is mediated by a signalling pathway including mitotic cyclin-dependent kinase 1 (CDK1) and diaphanous-related formin 1 (CYK1). Similar observations are also made using EHEC-infected human intestinal cells in vitro. Our results support the use of C. elegans as a host model for studying attaching and effacing lesions in vivo, and reveal that the CDK1-formin signal axis is necessary for EHEC-induced microvillar effacement.

Download Full-text

Biosynthesis and interconversion of Drosophila nuclear lamin isoforms during normal growth and in response to heat shock.

The Journal of Cell Biology ◽

10.1083/jcb.105.2.771 ◽

1987 ◽

Vol 105 (2) ◽

pp. 771-790 ◽

Cited By ~ 56

Author(s):

D E Smith ◽

Y Gruenbaum ◽

M Berrios ◽

P A Fisher

Keyword(s):

Heat Shock ◽

Nuclear Envelope ◽

Normal Growth ◽

Nuclear Lamina ◽

Culture Cells ◽

Nuclear Lamin ◽

In Vitro Processing ◽

Sds Page ◽

Differential Phosphorylation

Two major immunocross-reactive polypeptides of the Drosophila nuclear envelope, distinguishable in interphase cells on the basis of one-dimensional SDS-PAGE mobility, have been localized to the nuclear lamina by immunoelectron microscopy. These have been designated lamins Dm1 and Dm2. Both lamins are apparently derived posttranslationally from a single, primary translation product, lamin Dm0. A pathway has been established whereby lamin Dm0 is processed almost immediately upon synthesis in the cytoplasm to lamin Dm1. Processing occurs posttranslationally, is apparently proteolytic, and has been reconstituted from cell-free extracts in vitro. Processing in vitro is ATP dependent. Once assembled into the nuclear envelope, a portion of lamin Dm1 is converted into lamin Dm2 by differential phosphorylation. Throughout most stages of development and in Schneider 2 tissue culture cells, both lamin isoforms are present in approximately equal abundance. However, during heat shock, lamin Dm2 is converted nearly quantitatively into lamin Dm1. Implications for understanding the regulation of nuclear lamina plasticity through normal growth and in response to heat shock are discussed.

Download Full-text