A novel anti-WIP monoclonal antibody detects an isoform of WIP that lacks the WASP binding domain.
The majority of Wiskott-Aldrich syndrome protein (WASP) in T cells is in a complex with WASP interacting protein (WIP), a 503 a.a. long proline rich protein. Here we demonstrate that a novel anti-WIP mAb, 3D10, recognizes an epitope in the N-terminal domain of the WIP protein, within the sequence 13PTFALA18. mAb 3D10 competes with actin, but not with WASP or Nck, for WIP binding. Analysis of 3D10 immunoprecipitates failed to demonstrate dissociation of the WASP-WIP complex after TCR ligation that we previously reported using a polyclonal anti-WIP anti-serum raised against a C-terminal peptide (a.a. 459-503) that spanned the WASP binding site. 3D10 mAb allowed the detection of a novel isoform of WIP consisting of a truncated 403 a.a. long protein that includes the 377 a.a. encoded by the first 4 exons of WIP followed by a 26 a.a. sequence encoded by intron 4.
Koduru
Suresh
S
Division of Immunology, Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, MA 02115, USA.
Massaad
Michel
M
Wilbur
Christopher
C
Kumar
Lalit
L
Geha
Raif
R
Ramesh
Narayanaswamy
N
D000199:Actins / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D003598:Cytoskeletal Proteins; D000939:Epitopes / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D005260:Female; D047468:Immunoprecipitation; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D009154:Mutation; D015513:Oncogene Proteins / Q000378:metabolism; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D051316:Wiskott-Aldrich Syndrome Protein / Q000378:metabolism*
D000199:Actins; D048868:Adaptor Proteins, Signal Transducing; D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D000939:Epitopes; C078332:Nck protein; D015513:Oncogene Proteins; D020033:Protein Isoforms; D011948:Receptors, Antigen, T-Cell; C491671:Waspip protein, mouse; D051316:Wiskott-Aldrich Syndrome Protein