A conformational change within the WAVE2 complex regulates its degradation following cellular activation.
WASp family Verprolin-homologous protein-2 (WAVE2), a member of the Wiskott-Aldrich syndrome protein (WASp) family of actin nucleation promoting factors, is a central regulator of actin cytoskeleton polymerization and dynamics. Multiple signaling pathways operate via WAVE2 to promote the actin-nucleating activity of the actin-related protein 2/3 (Arp2/3) complex. WAVE2 exists as a part of a pentameric protein complex known as the WAVE regulatory complex (WRC), which is unstable in the absence of its individual proteins. While the involvement of WAVE2 in actin polymerization has been well documented, its negative regulation mechanism is poorly characterized to date. Here, we demonstrate that WAVE2 undergoes ubiquitylation in a T-cell activation dependent manner, followed by proteasomal degradation. The WAVE2 ubiquitylation site was mapped to lysine 45, located at the N-terminus where WAVE2 binds to the WRC. Using Förster resonance energy transfer (FRET), we reveal that the autoinhibitory conformation of the WRC maintains the stability of WAVE2 in resting cells; the release of autoinhibition following T-cell activation facilitates the exposure of WAVE2 to ubiquitylation, leading to its degradation. The dynamic conformational structures of WAVE2 during cellular activation dictate its degradation.
The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Noah
N
Joseph
The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Guy
G
Biber
The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Sophia
S
Fried
The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Barak
B
Reicher
The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Omer
O
Levy
The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Batel
B
Sabag
The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Elad
E
Noy
The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
Mira
M
Barda-Saad
D000596:Amino Acids / Q000378:metabolism; D002460:Cell Line; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D059748:Proteolysis; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D054875:Ubiquitination; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D000596:Amino Acids; D046912:Multiprotein Complexes; D011948:Receptors, Antigen, T-Cell; C120152:WASF2 protein, human; D051300:Wiskott-Aldrich Syndrome Protein Family