A Novel Function for Glutathione S-Transferase π in MAPK Pathway

Abstract: Glutathione S-Transeferases(GSTs) comprise a family of enzymes that contribute to cellular xenbiotic detoxfication. In particular， GSTπ/GSTpii/GSTpi is the most ubiquitous isozyme. Mitogen-activated protein kinase (MAPK) pathway can regulate the apoptosis， proliferation， differentiation and stress responses of eukaryotes. In 1999， a research group first demonstrated that GSTpi can modulate MAPK signal pathway， in which under non stressed conditions the monomeric form of GSTpi binds JNK and leads to JNK inhibition， while upon UV or H2O2 treatment， the dimerization or polymerization of GSTpi itself results in GSTpi-JNK complex disassociation and eventually the release of JNK inhibition， activated JNK by phosphorylation activates c-Jun， further activates the transcription of GSTpi， the newly synthesized monomeric GSTpi can inhibit JNK as feedback. GSTpi can also regulate the JNK upstream kinase ASK1 to protect cell from sirum withdrow. These researches uncovered a novel function for GSTpi to regulate MAPK signal transduction pathway other than changing the cellular ROS level by reducing the cellular xenbiotics.

CSTR: 32200.14.cjcb.2004.03.0009