The PPLA motif of glycogen synthase kinase 3beta is required for interaction with Fe65.
Glycogen synthase kinase 3beta (GSK 3 beta) is a serine/ threonine kinase that phosphorylates substrates such as beta-catenin and is involved in a variety of biological processes, including embryonic development, metabolism, tumorigenesis, and cell death. Here, we present evidence that human GSK 3beta is associated with Fe65, which has the characteristics of an adaptor protein, possessing a WW domain, and two phosphotyrosine interaction domains, PID1 and PID2. The GSK 3beta catalytic domain also contains a putative WW domain binding motif ((371)PPLA(374)), and we observed, using a pull down approach and co-immuno-precipitation, that it interacts physically with Fe65 via this motif. In addition, we detected co-localization of GSK 3beta and Fe65 by confocal microscopy, and this co-localization was disrupted by mutation of the putative WW domain binding motif of GSK 3beta.Finally, in transient transfection assays interaction of GSK 3 beta (wt) with Fe65 induced substantial cell apoptosis, whereas interaction with the GSK 3beta AALA mutant ((371)AALA(374)) did not, and we noted that phosphorylation of the Tyr 216 residue of the GSK 3beta AALA mutant was significantly reduced compared to that of GSK 3beta wild type. Thus, our observations indicate that GSK 3beta binds to Fe65 through its (371)PPLA(374) motif and that this interaction regulates apoptosis and phosphorylation of Tyr 216 of GSK 3beta.
School of Science Education, Chungbuk National University, Cheongju 361-763, Korea.
Eun Jeoung
EJ
Lee
Sunghee
S
Hyun
Jaesun
J
Chun
Sung Hwa
SH
Shin
Kyung Eun
KE
Lee
Kwang Hum
KH
Yeon
Tae Yoon
TY
Park
Sang Sun
SS
Kang
D020816:Amino Acid Motifs; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D008856:Microscopy, Fluorescence; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D014162:Transfection
C091042:APBB1 protein, human; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D011994:Recombinant Proteins; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3