Molecular cloning and expression pattern of porcine myeloid DAP12-associating lectin-1

DAP12 is an ITAM-bearing membrane protein that is associated with activatin g receptors in natural killer cells, granulocytes, macrophages, and monocyt es. Myeloid DAP12-associating lectin-l (MDL-1) is a type II membrane protei n that associates with DAP12. In this study, we report the molecular clonin g of two isoforms of porcine MDL-1 cDNA from pulmonary alveolar macrophages . The porcine MDL-1 short form has 165 amino acids and 70% sequence identit y with the mouse MDL-1 short form. The long form has 20 more amino acids in the stalk region and 71% sequence identity with human MDL-1 and 67% with t he mouse MDL-1 long form. Porcine MDL-I contains a conserved lysine in the transmembrane domain. There are six putative N-linked glycosylation sites i n the MDL-1 long form. MDL-1 transcripts were detected exclusively in macro phages and monocytes by RT-PCR. When transfected into 293 cells, porcine MD L-1 is expressed on the cell surface associated with DAP12, (C) 2001 Academ ic Press.