STRUCTURAL, FUNCTIONAL-ANALYSIS AND LOCALIZATION OF THE HUMAN CAP18 GENE

CAP18 is an antimicrobial protein found in specific granules of PMNs, The human CAP18 (HCAP18) gene was cloned from a human genomic phage li brary. Sequence analysis revealed the HCAP18 gene to have 4 exons span ning 3 kb, including 700 bp of upstream DNA, Using 3' RACE no homologs of human HCAP18 were found in human bone marrow or leukocyte populati ons, By PCR analysis of a somatic cell mapping panel and fluorescence in situ hybridization of a genomic clone to metaphase chromosomes the gene was mapped to chromosome band 3p21.3, Like several other genes ex pressed late in PMN development the CAP18 gene did not contain typical TATA box or CCAAT sequences, Expression in Cos 7 cells permitted limi ted mapping of the promoter function in upstream fragments of the HCAP 18 gene. Western blot, Northern blot and RT-PCR analysis show HCAP18 t o be produced specifically in granulocytes, This work forms the ground work for future analysis of the genetic regulation of this antimicrobi al protein during PMN differentiation.