PBX2 and PBX3, new homeobox genes with extensive homology to the human proto-oncogene PBX1
- Stanford Univ. Medical Center, CA (United States)
Two new homeobox genes, PBX2 and PBX3, were isolated on the basis of their extensive homology to PBX1, a novel human homeobox gene involved in t(1;19) translocation in acute pre-B-cell leukemias. The predicted pbx2 and pbx3 proteins are 92 and 94% identical to Pbx1 over a large region of 266 amino acids within and flanking their homeodomains, but all three proteins diverge significantly near their amino and carboxy termini. Chromosome in situ hybridizations demonstrated that the PBX genes are not clustered but map to separate chromosomal loci: PBX1, 1q23; PBX2, 3q22-23; PBX3, 9q33-34. Expression of PBX2 or PBX3 was not restricted to particular states of differentiation or development, as mRNA transcripts of these genes were detected in most fetal and adult tissues and all cell lines, unlike PBX1, which is not expressed in lymphoid cell lines. Similar to PBX1RNA, PBX3 RNA is alternatively spliced to yield two translation products with different carboxy termini, a feature not observed for PBX2. Their extensive sequence similarity and widespread expression suggest a generalized, overlapping role for Pbx proteins in most cell types. Differences in their amino and carboxy termini may modulate their activities, mediated in part by differential splicing and, for PBX1, protein fusion following t(1;19) chromosomal translocation.
- OSTI ID:
- 5089594
- Journal Information:
- Molecular and Cellular Biology; (United States), Vol. 11:12; ISSN 0270-7306
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HETEROCHROMOSOMES
GENETIC MAPPING
ONCOGENES
DNA SEQUENCING
TUMOR CELLS
CELL DIFFERENTIATION
AMINO ACID SEQUENCE
BIOLOGICAL EVOLUTION
LEUKEMIA
ANIMAL CELLS
CHROMOSOMES
DISEASES
GENES
IMMUNE SYSTEM DISEASES
MAPPING
MOLECULAR STRUCTURE
NEOPLASMS
STRUCTURAL CHEMICAL ANALYSIS
550400* - Genetics