Rare Diseases Symptoms Automatic Extraction

The Drosophila werner exonuclease participates in an exonuclease-independent response to replication stress.

[werner syndrome]

Members of the RecQ family of helicases are known for their roles in DNA repair, replication, and recombination. Mutations in the human RecQ helicases, WRN and BLM, cause Werner and Bloom syndromes, which are diseases characterized by genome instability and an increased risk of cancer. While WRN contains both a helicase and an exonuclease domain, the Drosophila melanogaster homolog, WRNexo, contains only the exonuclease domain. Therefore the Drosophila model system provides a unique opportunity to study the exonuclease functions of WRN separate from the helicase. We created a null allele of WRNexo via imprecise P-element excision. The null WRNexo mutants are not sensitive to double-strand break-inducing reagents, suggesting that the exonuclease does not play a key role in homologous recombination-mediated repair of DSBs. However, WRNexo mutant embryos have a reduced hatching frequency and larvae are sensitive to the replication fork-stalling reagent, hydroxyurea (HU), suggesting that WRNexo is important in responding to replication stress. The role of WRNexo in the HU-induced stress response is independent of Rad51. Interestingly, the hatching defect and HU sensitivity of WRNexo mutants do not occur in flies containing an exonuclease-dead copy of WRNexo, suggesting that the role of WRNexo in replication is independent of exonuclease activity. Additionally, WRNexo and Blm mutants exhibit similar sensitivity to HU and synthetic lethality in combination with mutations in structure-selective endonucleases. We propose that WRNexo and BLM interact to promote fork reversal following replication fork stalling and in their absence regressed forks are restarted through a Rad51-mediated process.

Diseases presenting "cancer" symptom

  • achondroplasia
  • acute rheumatic fever
  • adrenal incidentaloma
  • alpha-thalassemia
  • benign recurrent intrahepatic cholestasis
  • cadasil
  • canavan disease
  • carcinoma of the gallbladder
  • cholangiocarcinoma
  • coats disease
  • congenital adrenal hyperplasia
  • congenital diaphragmatic hernia
  • cowden syndrome
  • cushing syndrome
  • cutaneous mastocytosis
  • dedifferentiated liposarcoma
  • dystrophic epidermolysis bullosa
  • epidermolysis bullosa simplex
  • erdheim-chester disease
  • erythropoietic protoporphyria
  • esophageal adenocarcinoma
  • esophageal carcinoma
  • esophageal squamous cell carcinoma
  • familial hypocalciuric hypercalcemia
  • familial mediterranean fever
  • gm1 gangliosidosis
  • heparin-induced thrombocytopenia
  • hereditary cerebral hemorrhage with amyloidosis
  • hirschsprung disease
  • hodgkin lymphoma, classical
  • inclusion body myositis
  • junctional epidermolysis bullosa
  • kabuki syndrome
  • kallmann syndrome
  • kindler syndrome
  • lamellar ichthyosis
  • liposarcoma
  • locked-in syndrome
  • lymphangioleiomyomatosis
  • monosomy 21
  • neuralgic amyotrophy
  • oculocutaneous albinism
  • oligodontia
  • oral submucous fibrosis
  • papillon-lefèvre syndrome
  • pendred syndrome
  • pleomorphic liposarcoma
  • primary effusion lymphoma
  • proteus syndrome
  • pyomyositis
  • pyruvate dehydrogenase deficiency
  • severe combined immunodeficiency
  • sneddon syndrome
  • systemic capillary leak syndrome
  • triple a syndrome
  • von hippel-lindau disease
  • waldenström macroglobulinemia
  • well-differentiated liposarcoma
  • werner syndrome
  • wiskott-aldrich syndrome
  • wolf-hirschhorn syndrome
  • x-linked adrenoleukodystrophy

This symptom has already been validated