Abl family kinases and Cbl cooperate with the Nck adaptor to modulate Xenopus development.
We previously showed that overexpression of the Nck Src homology (SH) 2/SH3 adaptor in Xenopus embryos induced developmental defects including anterior truncation and mesoderm ventralization. Mutagenic analysis indicated that this was due to relocalization of endogenous proteins that bind the first two SH3 domains of Nck. We therefore screened a Xenopus expression library with Nck SH3 domains to identify Nck-interacting proteins, and evaluated candidate binding proteins for a potential role in Nck-induced anterior truncation/ventralization. Of 39 binding proteins analyzed, only the Abl-related kinase Arg and the Cbl proto-oncogene product bound preferentially to the first two SH3 domains in tandem compared with the individual domains, consistent with a role in the developmental phenotype. High level overexpression of c-Abl or Arg alone induced anterior truncation, as did lower levels of an activated form of Abl; Cbl alone had no effect. In a sensitized system where subthreshold amounts of a ventralizing Nck mutant were expressed, co-expression of the combination of Abl or Arg and Cbl at modest levels strongly potentiated anterior truncation, while Arg, Abl, or Cbl alone were without effect. These results suggest a role for both Cbl and Abl family kinases in patterning the Xenopus embryo.
Adler
C E
CE
Laboratory of Molecular Medicine, Children's Hospital and Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Miyoshi-Akiyama
T
T
Aleman
L M
LM
Tanaka
M
M
Smith
J M
JM
Mayer
B J
BJ
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001665:Binding Sites; D019521:Body Patterning; D002460:Cell Line; D003001:Cloning, Molecular; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D006801:Humans; D008648:Mesoderm / Q000201:enzymology / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D050722:Oncogene Protein v-cbl; D015513:Oncogene Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D011233:Precipitin Tests; D011485:Protein Binding; D000090063:Proto-Oncogene Mas; D016315:Proto-Oncogene Proteins c-abl / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D018909:src Homology Domains
D048868:Adaptor Proteins, Signal Transducing; C000715470:MAS1 protein, human; C078332:Nck protein; D050722:Oncogene Protein v-cbl; D015513:Oncogene Proteins; D000090063:Proto-Oncogene Mas; D012333:RNA, Messenger; D015682:Retroviridae Proteins, Oncogenic; D016315:Proto-Oncogene Proteins c-abl