WIP is a chaperone for Wiskott-Aldrich syndrome protein (WASP).
Wiskott-Aldrich syndrome protein (WASP) is in a complex with WASP-interacting protein (WIP). WASP levels, but not mRNA levels, were severely diminished in T cells from WIP(-/-) mice and were increased by introduction of WIP in these cells. The WASP binding domain of WIP was shown to protect WASP from degradation by calpain in vitro. Treatment with the proteasome inhibitors MG132 and bortezomib increased WASP levels in T cells from WIP(-/-) mice and in T and B lymphocytes from two WAS patients with missense mutations (R86H and T45M) that disrupt WIP binding. The calpain inhibitor calpeptin increased WASP levels in activated T and B cells from the WASP patients, but not in primary T cells from the patients or from WIP(-/-) mice. Despite its ability to increase WASP levels proteasome inhibition did not correct the impaired IL-2 gene expression and low F-actin content in T cells from the R86H WAS patient. These results demonstrate that WIP stabilizes WASP and suggest that it may also be important for its function.
de la Fuente
Miguel A
MA
Division of Immunology, Children's Hospital Boston, One Blackfan Circle, Boston, MA 02115, USA.
Sasahara
Yoji
Y
Calamito
Marco
M
Antón
Inés M
IM
Elkhal
Abdallah
A
Gallego
Maria D
MD
Suresh
Koduru
K
Siminovitch
Katherine
K
Ochs
Hans D
HD
Anderson
Kenneth C
KC
Rosen
Fred S
FS
Geha
Raif S
RS
Ramesh
Narayanaswamy
N
D000199:Actins / Q000378:metabolism; D000818:Animals; D001120:Arginine / Q000235:genetics / Q000378:metabolism; D001897:Boronic Acids / Q000494:pharmacology; D000069286:Bortezomib; D002154:Calpain / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D047908:Intracellular Signaling Peptides and Proteins; D019169:Jurkat Cells; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D020125:Mutation, Missense / Q000235:genetics; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D011485:Protein Binding; D011719:Pyrazines / Q000494:pharmacology; D014923:Wiskott-Aldrich Syndrome / Q000235:genetics / Q000378:metabolism*; D051316:Wiskott-Aldrich Syndrome Protein / Q000378:metabolism*
D000199:Actins; D001897:Boronic Acids; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D007376:Interleukin-2; D047908:Intracellular Signaling Peptides and Proteins; D018832:Molecular Chaperones; D061988:Proteasome Inhibitors; D011719:Pyrazines; C109903:WIPF1 protein, human; C491671:Waspip protein, mouse; D051316:Wiskott-Aldrich Syndrome Protein; D000069286:Bortezomib; D001120:Arginine; D002154:Calpain; D046988:Proteasome Endopeptidase Complex