BCL8 Is a Novel, Evolutionarily Conserved Human Gene Family Encoding Proteins with Presumptive Protein Kinase A Anchoring Function

Abstract BCL8 is a novel human gene family initially identified through cloning of BCL8A , located at the t(14;15)(q32;q11–q13) translocation breakpoint, in a case of diffuse large B-cell lymphoma. Multiple copies of BCL8A map to the 1-Mb proximal duplicated region at 15q. We identified additional copies on human chromosomes 13 ( BCL8B ), 22 ( BCL8C ), 2 ( BCL8D ), and 10 ( BCL8E ) by cDNA cloning and sequence analysis. BCL8A , BCL8C , BCL8D , and BCL8E are truncated at the genomic level and are presumably pseudogenes or sterile transcripts. BCL8B is expressed predominantly in human brain and encodes a 327-kDa protein with extensive homology to the Drosophila melanogaster protein kinase A anchoring protein RG. LRBA , a human gene with a ubiquitous expression pattern mapping to 4q32, encodes a protein closely related to BCL8. The phylogenetically conserved BCL8 gene family evolved by transchromosomal and intrachromosomal duplications within the human genome.