ABSTRACT
We have identified a novel gene encoding a protein designated DLEC (dendritic cell lectin), which is a type II membrane glycoprotein of 213 amino acids and belongs to the human calcium-dependent (C-type) lectin family. The cytoplasmic tail of DLEC lacks consensus signaling motifs and its extracellular region shows a single carbohydrate recognition domain (CRD), closest in homology to the dendritic cell immunoreceptor (DCIR) CRD. The DLEC gene has been localized linked to DCIR on the telomeric region of the NK gene complex. RT-PCR and Northern blot analyses show that DLEC mRNA is preferentially expressed in monocyte-derived dendritic cells.
Subject(s)
Dendritic Cells/immunology , Lectins/biosynthesis , Lectins/genetics , Monocytes/immunology , Nerve Tissue Proteins/biosynthesis , Nerve Tissue Proteins/genetics , Receptors, Immunologic , Alternative Splicing , Amino Acid Sequence , Base Sequence , Cells, Cultured , Cloning, Molecular , Genetic Linkage , Humans , Lectins/chemistry , Lectins, C-Type , Membrane Glycoproteins/genetics , Molecular Sequence Data , Nerve Tissue Proteins/chemistry , Phylogeny , Protein Structure, Tertiary , RNA, Messenger/biosynthesis , Receptors, Mitogen/genetics , Sequence Homology, Amino Acid , Tissue DistributionABSTRACT
The killer cell lectin-like receptor (KLR) family is formed by type II transmembrane glycoproteins with a single extracellular C-type lectin-like domain (CTLD). Some of these glycoproteins are involved in the regulation of natural killer cell activity. Recently, we have described the molecular characterization of the KLRF1 gene and the existence of one alternative spliced form, lacking the stalk region of the extracellular domain. In this work we describe two novel KLRF1 alternative spliced variants coding for truncated proteins lacking the CTLD. In addition, we present the biochemical analysis of the KLRF1 protein and the subcellular distribution of all KLRF1 isoforms expressed in heterologous transfectants.
