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Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c
07:42

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Published on: June 29, 2011

EnABLing microprocessor for apoptosis

Chi-Chiang Tu1, Jean Y J Wang1

  • 1Department of Medicine, Division of Hematology-Oncology, Moores Cancer Center, University of California, San Diego, School of Medicine, La Jolla, CA.

Molecular & Cellular Oncology
|May 17, 2016
PubMed

Insights

The Microprocessor complex, including DROSHA and DGCR8, processes microRNAs. Abelson tyrosine kinase 1 (ABL) phosphorylates DGCR8, regulating pro-apoptotic microRNA processing and expanding ABL

Area of Science:

  • Molecular Biology
  • RNA Processing
  • Biochemistry

Background:

  • The Microprocessor complex, comprising DROSHA and DGCR8, is essential for microRNA biogenesis.
  • MicroRNAs (miRNAs) are key regulators of gene expression.
  • Abelson tyrosine kinase 1 (ABL) is known for its role in cell signaling and proliferation.

Purpose of the Study:

  • To investigate the role of Abelson tyrosine kinase 1 (ABL) in microRNA processing.
  • To determine how ABL interacts with the Microprocessor complex.
  • To elucidate the functional consequences of ABL-mediated regulation of miRNA biogenesis.

Main Methods:

  • Biochemical assays to study protein-protein interactions.
  • In vitro kinase assays to assess DGCR8 phosphorylation by ABL.
  • Analysis of pri-miRNA processing in cells with altered ABL activity.

Main Results:

  • Abelson tyrosine kinase 1 (ABL) directly phosphorylates DGCR8, a component of the Microprocessor complex.
  • Phosphorylation of DGCR8 by ABL enhances the cleavage of specific precursor microRNA hairpins (pre-miRNAs).
  • This regulation specifically affects a subset of pro-apoptotic pri-miRNAs.

Conclusions:

  • Abelson tyrosine kinase 1 (ABL) phosphorylates DGCR8, modulating the Microprocessor complex's activity.
  • ABL's nuclear function extends to the regulation of RNA processing, specifically miRNA biogenesis.
  • This finding reveals a novel mechanism linking kinase activity to the regulation of pro-apoptotic gene expression via miRNAs.
Keywords:
ABLBCR-ABLDGCDNA damage responseDROSHAR8tyrosine phosphorylation

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