Rosenblatt J (2012) Curr Biol "Programmed cell death: a new way worms get rid of unwanted cells."

Rosenblatt J

[Curr Biol, 2012]

The genetics and predictable cell death lineages in Caenorhabditis elegans have been critical for identifying a conserved apoptosis pathway. Yet, cells still die in mutants that disrupt this pathway. A recent study shows that this death occurs by cell shedding.

Holbert S et al. (2001) Proc Natl Acad Sci U S A "The Gln-Ala repeat transcriptional activator CA150 interacts with huntingtin: neuropathologic and genetic evidence for a role in Huntington's disease pathogenesis."

Holbert S, Ferrante RJ, Kiechle T, Hayden MR, Ross CA, Dausset J, Denghien I, Wellington C, Margolis RL, Neri C, Rosenblatt A

[Proc Natl Acad Sci U S A, 2001]

Huntington's disease (HD) is a neurodegenerative disease caused by polyglutamine expansion on the protein huntingtin (htt). Pathogenesis in HD appears to involve the formation of ubiquitinated neuronal intranuclear inclusions containing N-terminal mutated htt, abnormal protein interactions, and the aggregate sequestration of a variety of proteins (noticeably, transcription factors). To identify novel htt-interacting proteins in a simple model system, we used a yeast two-hybrid screen with a Caenorhabditis elegans activation domain library. We found a predicted WW domain protein (ZK1127.9) that interacts with N-terminal fragment of htt in two-hybrid tests. A human homologue of ZK1127.9 is CA150, a transcriptional coactivator with a N-terminal insertion that contains an imperfect (Gln-Ala) tract encoded by a polymorphic repeat DNA. CA150 interacted in vitro with full-length htt from lymphoblastoid cells. The expression of CA150, measured immunohistochemically, was markedly increased in human HD brain tissue compared with normal age-matched human brain tissue, and CA150 showed aggregate formation with partial colocalization to ubiquitin-positive aggregates. In 432 HD patients, the CA150 repeat length explains a small, but statistically significant, amount of the variability in the onset age. Our data suggest that abnormal expression of CA150, mediated by interaction with polyglutamine-expanded htt, may alter transcription and have a role in HD

Mats Holmberg et al. (2008) European Worm Meeting "Modifiers of aggregation in neurodegenerative diseases"

Tjakko van Ham T, Ellen Nollen, Jeroen van Rheenen, Mats Holmberg

[European Worm Meeting, 2008]

Inheritable expansions of polyglutamine tracts lead to misfolding of the. affected protein in at least nine neurodegenerative diseases. Although all. are characterized by the accumulation of inclusions, increasing evidence. point to smaller, monomeric or oligomeric precursors as the toxic species. and suggest an active, protective sequestration of misfolded protein. It. has previously been established that genetic factors, other then the. unstable extended CAG repeat, affect the age of onset as well as disease. progression1. Screens for modifiers of polyglutamine, by for example RNAi,. makes it increasingly clear that disease related misfolding is influenced. by a large network of genes involved in different cellular processes2. We. aim to identify and characterise modifiers of polyglutamine aggregation and. toxicity in C. elegans expressing YFP-tagged polyglutamine. Aggregation can. be followed in time and screened for by observing fluorescent foci in. polyglutamine strains. Cytotoxicity has been shown in these strains to. correlate with longer glutamine tracts. In a forward mutagenesis screen in. a C. elegans model of polyglutamine disorders, we identified a missense. mutation in Moag-4 (modifier of aggregation), causing a reduction of. aggregation and a polyglutamine threshold specific increase in toxicity.. The influence on inclusion formation is confirmed by gene knockout and RNAi. knockdown. Our results implicate moag-4 in the active sequestration of. misfolded protein under cellular stress and therefore in a novel category. of stress response. 1 Rosenblatt et al. Am J Med Genet. 2001 Jul 8;105(5):399-403. Familial. influence on age of onset among siblings with Huntington disease.. 2 Nollen et. al. Proc Natl Acad Sci U S A. 2004 Apr 27;101(17):6403-8.. Genome-wide RNA interference screen identifies previously undescribed. regulators of polyglutamine aggregation.

Quartey MO et al. (2021) Sci Rep "The A(1-38) peptide is a negative regulator of the A(1-42) peptide implicated in Alzheimer disease progression."

Pennington PR, Heistad RM, Nyarko JNK, Barnes JR, Bolanos MAC, Parsons MP, Knudsen KJ, De Carvalho CE, Leary SC, Mousseau DD, Buttigieg J, Maley JM, Quartey MO

[Sci Rep, 2021]

The pool of -Amyloid (A) length variants detected in preclinical and clinical Alzheimer disease (AD) samples suggests a diversity of roles for A peptides. We examined how a naturally occurring variant, e.g. A(1-38), interacts with the AD-related variant, A(1-42), and the predominant physiological variant, A(1-40). Atomic force microscopy, Thioflavin T fluorescence, circular dichroism, dynamic light scattering, and surface plasmon resonance reveal that A(1-38) interacts differently with A(1-40) and A(1-42) and, in general, A(1-38) interferes with the conversion of A(1-42) to a -sheet-rich aggregate. Functionally, A(1-38) reverses the negative impact of A(1-42) on long-term potentiation in acute hippocampal slices and on membrane conductance in primary neurons, and mitigates an A(1-42) phenotype in Caenorhabditis elegans. A(1-38) also reverses any loss of MTT conversion induced by A(1-40) and A(1-42) in HT-22 hippocampal neurons and APOE 4-positive human fibroblasts, although the combination of A(1-38) and A(1-42) inhibits MTT conversion in APOE 4-negative fibroblasts. A greater ratio of soluble A(1-42)/A(1-38) [and A(1-42)/A(1-40)] in autopsied brain extracts correlates with an earlier age-at-death in males (but not females) with a diagnosis of AD. These results suggest that A(1-38) is capable of physically counteracting, potentially in a sex-dependent manner, the neuropathological effects of the AD-relevant A(1-42).

Danielle Thierry-Mieg et al. (2003) Worm Breeder's Gazette "www.wormgenes.org , a new gene centered database"

Vahan Simonyan, Michel Potdevin, Mark Sienkiewicz, Yuji KOHARA, Jean Thierry-Mieg, Danielle Thierry-Mieg, Tadasu SHIN-I

[Worm Breeder's Gazette, 2003]

Wormgenes is a new resource for C.elegans offering a detailed summary about each gene and a powerful query system.

Tangrodchanapong T et al. (2020) Front Pharmacol "Frondoside A Attenuates Amyloid- Proteotoxicity in Transgenic Caenorhabditis elegans by Suppressing Its Formation."

Tangrodchanapong T, Sobhon P, Meemon K

[Front Pharmacol, 2020]

Oligomeric assembly of Amyloid- (A) is the main toxic species that contribute to early cognitive impairment in Alzheimer's patients. Therefore, drugs that reduce the formation of A oligomers could halt the disease progression. In this study, by using transgenic <i>Caenorhabditis elegans</i> model of Alzheimer's disease, we investigated the effects of frondoside A, a well-known sea cucumber <i>Cucumaria frondosa</i> saponin with anti-cancer activity, on A aggregation and proteotoxicity. The results showed that frondoside A at a low concentration of 1 M significantly delayed the worm paralysis caused by A aggregation as compared with control group. In addition, the number of A plaque deposits in transgenic worm tissues was significantly decreased. Frondoside A was more effective in these activities than ginsenoside-Rg3, a comparable ginseng saponin. Immunoblot analysis revealed that the level of small oligomers as well as various high molecular weights of A species in the transgenic <i>C. elegans</i> were significantly reduced upon treatment with frondoside A, whereas the level of A monomers was not altered. This suggested that frondoside A may primarily reduce the level of small oligomeric forms, the most toxic species of A. Frondoside A also protected the worms from oxidative stress and rescued chemotaxis dysfunction in a transgenic strain whose neurons express A. Taken together, these data suggested that low dose of frondoside A could protect against A-induced toxicity by primarily suppressing the formation of A oligomers. Thus, the molecular mechanism of how frondoside A exerts its anti-A aggregation should be studied and elucidated in the future.

Hodgkin JA (1998) International Journal of Developmental Biology "Seven types of pleiotropy."

Hodgkin JA

[International Journal of Developmental Biology, 1998]

Pleiotropy , a situation in which a single gene influences multiple phenotypic tra its, can arise in a variety of ways. This paper discusses possible underlying mechanisms and proposes a classification of the various phenomena involved.

Tuck S (2011) Curr Biol "Extracellular vesicles: budding regulated by a phosphatidylethanolamine translocase."

Tuck S

[Curr Biol, 2011]

Recent work on a Caenorhabditis elegans transmembrane ATPase reveals a central role for the aminophospholipid phosphatidylethanolamine in the production of a class of extracellular vesicles.

Viney ME et al. (2004) Naturwissenschaften "Is dauer pheromone of Caenorhabditis elegans really a pheromone?"

Viney ME, Franks NR

[Naturwissenschaften, 2004]

Animals respond to signals and cues in their environment. The difference between a signal (e.g. a pheromone) and a cue (e.g. a waste product) is that the information content of a signal is subject to natural selection, whereas that of a cue is not. The model free-living nematode Caenorhabditis elegans forms an alternative developmental morph (the dauer larva) in response to a so-called 'dauer pheromone', produced by all worms. We suggest that the production of 'dauer pheromone' has no fitness advantage for an individual worm and therefore we propose that 'dauer pheromone' is not a signal, but a cue. Thus, it should not be called a pheromone.

Schaeffer JM et al. (1990) J Antibiot (Tokyo) "Cochlioquinone A, a nematocidal agent which competes for specific [3H]ivermectin binding sites."

Williamson JM, Schaeffer JM, Bergstrom AR, Liesch JM, Goetz MA, Frazier EG

[J Antibiot (Tokyo), 1990]

Cochlioquinone A, isolated from the fungus Helminthosporium sativum, was found to have nematocidal activity. Cochlioquinone A is a competitive inhibitor of specific [3H]ivermectin binding suggesting that cochlioquinone A and ivermectin interact with the same membrane receptor.