The c-cbl proto-oncogene is preferentially expressed in thymus and testis tissue and encodes a nuclear protein.
Cas NS-1 is an acutely transforming murine retrovirus that induces early B-lineage lymphomas and occasional myeloid leukemias. The transforming sequence of this virus, v-cbl, shows no homology to known oncogenes but has some similarities to the yeast transcriptional factor GCN4. In this study we used a v-cbl probe to analyze mRNAs from a wide range of murine and human hemopoietic tumor cell lines and detected an 11-kilobase mRNA in all lineages. In normal mouse tissues the expression of c-cbl was highest in testis and thymus tissues, the predominant species in testis tissue being a 3.5-kilobase mRNA. The v-cbl oncogene was inserted into a bacterial expression vector to produce protein for the immunization of rabbits. Affinity-purified v-cbl antibodies identified abundant levels of p100gag-cbl in Cas NS-1-transformed fibroblasts and lower levels of a 135-kilodalton protein (p135c-cbl) in both normal and transformed cells. Subcellular fractionation showed that p100gag-cbl and p135c-cbl are both located in the nucleus and retained following 420 mM salt extraction. These results indicate that the translational product of a c-cbl is a 135-kilodalton nuclear protein.
Langdon
W Y
WY
Division of Human Immunology, Institute of Medical and Veterinary Science, Adelaide, South Australia.
Hyland
C D
CD
Grumont
R J
RJ
Morse
H C
HC
D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D015870:Gene Expression; D005822:Genetic Vectors; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D006801:Humans; D007938:Leukemia; D008297:Male; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics*; D050722:Oncogene Protein v-cbl; D009928:Organ Specificity; D000090063:Proto-Oncogene Mas; D011519:Proto-Oncogenes; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D015183:Restriction Mapping; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics*; D013737:Testis / Q000378:metabolism*; D013950:Thymus Gland / Q000378:metabolism*; D014158:Transcription, Genetic
C000715470:MAS1 protein, human; D009687:Nuclear Proteins; D050722:Oncogene Protein v-cbl; D000090063:Proto-Oncogene Mas; D012333:RNA, Messenger; D015682:Retroviridae Proteins, Oncogenic