LOCALIZATION OF THE HUMAN GENE FOR SRC-RELATED PROTEIN-TYROSINE KINASE LYN TO CHROMOSOME 8Q11-12 - A LYMPHOID SIGNALING CLUSTER

A member of the Src family of protein tyrosine kinases, Lyn is involve d in the signaling pathways for cytokine or immunoglobulin-stimulated blood cells. Lyn is especially prominent in B-cell function. We have f ine mapped LYN to chromosome 8q11-12 by fluorescence in situ hybridiza tion. Of note, the gene for the pre-B cell growth factor, interleukin 7 (IL-7), has been mapped to 8q12-13. We show that IL-7 increases the protein tyrosine kinase activity of Lyn in the Daudi B-cell line. A th ird gene, HYRC, whose product may be involved in immunoglobulin rearra ngement, has recently been localized to 8q11. We postulate that a lymp hoid signaling region exists at 8q11-13.