GENOMIC ORGANIZATION AND CHROMOSOMAL LOCALIZATION OF A MEMBER OF THE MAP KINASE PHOSPHATASE GENE FAMILY TO HUMAN-CHROMOSOME 11P15.5 AND A PSEUDOGENE TO 10Q11.2

Mitogen-activated protein kinase phosphatases (MKPs) play a central ro le in a variety of signaling pathways. We recently described a novel m urine MKP, M3/6, which is uniquely specific for c-Jun N-terminal kinas e/ stress-activated protein kinase and p38 kinase. Here we report the localization of the human orthologue of this gene, HB5, to within 150 kb of H19 an human chromosome 11p15.5. The gene consists of six exons. Two of the introns in HB5 are not found in other genes of this family , suggesting an evolutionary split between MKPs displaying specificity toward different MAP kinases. An intronless pseudogene is present on chromosome 10q11.2. Although 11p15.5 is an imprinted region, HB5 is al most entirely unmethylated on both alleles in lymphocytes. Chromosome 11p15 has been implicated in the development of a number of tumor type s, including luny, a tissue known to express this gene. Loss of hetero zygosity was found in one of eight informative lung tumors studied. (C ) 1997 Academic Press.