The SH2 domain of P210BCR/ABL is not required for the transformation of hematopoietic factor-dependent cells.

Abstract

Src-homology region 2 (SH2) domains, by binding to tyrosine-phosphorylated sequences, mediate specific protein-protein interactions important in diverse signal transduction pathways. Previous studies have shown that activated forms of the Abl tyrosine kinase, including P210BCR/ABL of human chronic myelogenous leukemia, require the SH2 domain for the transformation of fibroblasts. To determine whether SH2 is also required for Bcr/Abl to transform hematopoietic cells, we have studied two SH2 domain mutations in P210BCR/ABL: a point mutation in the conserved FLVRES motif (P210/R1033K), which interferes with phosphotyrosine-binding by SH2, and a complete deletion of SH2 (P210/delta SH2). Despite a negative effect on intrinsic Abl kinase activity, both P210 SH2 mutants were still able to transform the hematopoietic factor-dependent cell lines Ba/F3 and FDC-P1 to growth factor independence. Unexpectedly, both mutants showed greater transforming activity than wild-type P210 in a quantitative transformation assay, probably as a consequence of increased stability of the SH2 mutant proteins in vivo. Cells transformed by both P210 SH2 mutants were leukemogenic in synaptic mice and P210/r1053K mice exhibited a distinct disease phenotype, reminiscent of that induced by v-Abl. These results demonstrate that while the Abl SH2 domain is essential for BCR/ABL transformation of fibroblasts, it is dispensable for the transformation of hematopoietic factor-dependent cell lines.

• Authors: R L Ilaria Jr, R A Van Etten
• Journal: Blood (Blood) Vol. 86 Issue 10 Pg. 3897-904 (Nov 15 1995) ISSN: 0006-4971 [Print] United States
• PMID: 7579359 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Culture Media, Conditioned
• Hematopoietic Cell Growth Factors
• Recombinant Fusion Proteins
• Fusion Proteins, bcr-abl

Topics

• Amino Acid Sequence
• Animals
• Cell Transformation, Neoplastic (genetics)
• Culture Media, Conditioned (pharmacology)
• Fusion Proteins, bcr-abl (chemistry, metabolism, physiology)
• Hematopoietic Cell Growth Factors (pharmacology)
• Hematopoietic Stem Cells (drug effects, pathology)
• Humans
• Mice
• Mice, Inbred BALB C
• Mice, Nude
• Molecular Sequence Data
• Mutagenesis, Site-Directed
• Phenotype
• Phosphorylation
• Point Mutation
• Protein Processing, Post-Translational
• Recombinant Fusion Proteins (metabolism)
• Structure-Activity Relationship
• Transfection
• src Homology Domains