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Dismantling the Apoptotic Cell

  1. Paula Deming1,
  2. Sally Kornbluth2

Published Online: 15 DEC 2009

DOI: 10.1002/9780470015902.a0021564

eLS

eLS

How to Cite

Deming, P. and Kornbluth, S. 2009. Dismantling the Apoptotic Cell. eLS. .

Author Information

  1. 1

    University of Vermont, Burlington, Vermont, USA

  2. 2

    Duke University, Durham, North Carolina, USA

Publication History

  1. Published Online: 15 DEC 2009

This is not the most recent version of the article. View current version (20 MAR 2017)

Abstract

Apoptosis is a programme of cell death that results in dramatic morphological and biochemical changes in the dying cell due to the systematic dismantling of cellular architecture and functional pathways. The proteins that execute the apoptotic programme are a group of proteases termed caspases (cysteine-dependent aspartate-specific protease). Caspases proteolytically cleave a host of cellular substrates at aspartate residues, which may render them either functionally inactive or confer novel activities that help to promote cellular demise. Substrates targeted by caspases during the apoptotic programme include proteins involved in maintaining various aspects of cytoskeletal and organelle architecture as well as proteins that function in signalling networks critical for cell function. Following the execution phase of apoptosis, the cellular corpse is packaged in an orderly fashion into membrane-bound apoptotic bodies that are sensed by phagocytes, which neatly engulf the dead cell without eliciting an immune response.

Key concepts:

  • Apoptotic caspases are cysteine proteases which become activated in response to diverse extracellular and intracellular stimuli and subsequently carry out the cell death programme by systematically cleaving intracellular proteins.

  • A hierarchy of caspase activation exists whereby initiator caspases become activated to cleave and activate effector caspases, which then dismantle the cell through proteolytical cleavage of intracellular.

  • The cellular morphological changes associated with apoptosis encompass three stages: release, membrane blebbing and condensation.

  • Caspase-mediated cleavage of target proteins may produce stable functional effector fragments or unstable fragments that are quickly degraded.

  • Caspases target multiple aspects of the cellular architecture to induce collapse of organelles and the cytoskeleton.

  • Signalling networks that regulate cellular processes critical for cell survival are inactivated by caspases.

  • As the dying cell is dismantled during the apoptotic process, it orchestrates its own disposal by displaying ‘eat me’ signals on its cell surface and releasing ‘find me’ signals to recruit phagocytic cells.

Keywords:

  • initiator caspase;
  • effector caspase;
  • membrane blebbing;
  • nuclear disintegration;
  • cellular condensation;
  • apoptotic bodies