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Specific interaction of protein tyrosine phosphatase-MEG2 with phosphatidylserine

Runxiang Zhao1, Xueqi Fu, Qingshan Li

  • 1Hematology/Oncology Division, Department of Medicine, Vanderbilt University, Nashville, Tennessee 37232, USA.

The Journal of Biological Chemistry
|April 19, 2003
PubMed

Insights

Protein tyrosine phosphatase (PTP)-MEG2 binds phosphatidylserine via its Sec14 domain. This interaction influences PTP-MEG2 localization within cells, potentially regulating the clearance of apoptotic cells.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Protein tyrosine phosphatase (PTP)-MEG2 is an intracellular enzyme with a Sec14 homology domain.
  • Phosphatidylserine (PS) is a cell membrane phospholipid with a known role in apoptotic cell clearance.

Purpose of the Study:

  • To investigate the biochemical properties and cellular functions of PTP-MEG2.
  • To determine the specific lipid-binding capabilities of PTP-MEG2 and the role of its Sec14 domain.

Main Methods:

  • Purification of recombinant full-length and truncated PTP-MEG2.
  • Lipid-membrane overlay and liposome binding assays.
  • Cellular localization studies in human 293 cells.

Main Results:

  • PTP-MEG2 specifically binds phosphatidylserine (PS) among over 20 tested lipids.
  • The N-terminal Sec14 domain mediates PS binding.
  • The Sec14 domain directs PTP-MEG2 to the perinuclear region and plasma membrane in response to PS.

Conclusions:

  • PTP-MEG2's interaction with phosphatidylserine is mediated by its Sec14 domain.
  • This binding influences PTP-MEG2's subcellular localization.
  • PTP-MEG2 may regulate signaling pathways involved in apoptotic cell phagocytosis.

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