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Pro-EMAP II is not primarily cleaved by caspase-3 and -7

F R Zhang1, M A Schwarz

  • 1Departments of Pediatrics, Cardiothoracic Surgical Research, and Surgery, Childrens Hospital Research Institute, Los Angeles 90027, USA.

American Journal of Physiology. Lung Cellular and Molecular Physiology
|May 11, 2002
PubMed

Insights

The active form of Endothelial Monocyte-Activating Polypeptide II (EMAP II) has antiangiogenic properties. This study found that caspase-3 or -7 do not release active EMAP II, suggesting other enzymes are involved.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Cell Biology

Background:

  • Endothelial monocyte-activating polypeptide II (EMAP II), also known as p43, is a cytokine with known antiangiogenic properties.
  • The precise mechanism and enzymes responsible for releasing the active mature form of EMAP II from its precursor remain largely uncharacterized.

Purpose of the Study:

  • To investigate the proteolytic enzymes involved in the cleavage and release of active mature EMAP II.
  • To determine if caspase-3 or caspase-7 are responsible for processing pro-EMAP II.

Main Methods:

  • In vitro cleavage assays using purified pro-EMAP II.
  • In vivo studies to assess caspase-3 and caspase-7 activity in relation to EMAP II processing.

Main Results:

  • Purified pro-EMAP II was not cleaved by either caspase-3 or caspase-7, contrary to previous assumptions.
  • The findings indicate that caspase-3 and caspase-7 are not the primary enzymes responsible for releasing active EMAP II.

Conclusions:

  • The release of active EMAP II, which induces apoptosis in endothelial cells, likely involves proteolytic pathways distinct from caspase-3 and caspase-7.
  • Further research is needed to identify the specific proteases responsible for EMAP II maturation and its antiangiogenic function.

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