Molecular cloning and functional characterization of a human scavenger receptor with C-type lectin (SRCL), a novel member of a scavenger receptor family.
Using a human placenta cDNA library, we cloned a novel member belonging to the scavenger receptor family. Complementary DNA of this clone encodes a type II transmembranous glycoprotein containing a collagen-like domain, which are typical structural characteristics of scavenger receptor class A. This protein also contains a C-type lectin/carbohydrate recognition domain (C-type CRD) located at the C-terminus. We designated this as Scavenger Receptor with C-type Lectin (SRCL) type I. We also isolated human SRCL type II, which lacks the C-type CRD. Northern blot analysis revealed that hSRCL type I and type II mRNAs are abundantly expressed in adult human tissues. When hSRCL type I and type II were expressed in CHO-K1 cells, they were localized in the plasma membrane forming clusters on the surface. Ligand-binding studies of CHO-K1 cells expressing hSRCL type I and type II demonstrated their specific binding capacity in Escherichia coli and Staphylococcus aureus. These results indicate that hSRCL is a novel bacteria-binding receptor containing a C-type CRD and this receptor may play an important role in host defense.
Nakamura
K
K
Division of Biochemistry, Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan. nakamura@onbich.med.osaka-u.ac.jp
Funakoshi
H
H
Miyamoto
K
K
Tokunaga
F
F
Nakamura
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D016466:CHO Cells; D002462:Cell Membrane / Q000378:metabolism; D002874:Chromosome Mapping; D002887:Chromosomes, Human, Pair 18; D003001:Cloning, Molecular; D003094:Collagen / Q000737:chemistry; D037222:Collectins; D006224:Cricetinae; D018076:DNA, Complementary / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D015723:Gene Library; D006023:Glycoproteins / Q000737:chemistry; D006801:Humans; D007150:Immunohistochemistry; D008024:Ligands; D008565:Membrane Proteins; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008969:Molecular Sequence Data; D010920:Placenta / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B; D017386:Sequence Homology, Amino Acid; D013211:Staphylococcus aureus / Q000378:metabolism; D014018:Tissue Distribution
C422442:COLEC12 protein, human; D037222:Collectins; D018076:DNA, Complementary; D006023:Glycoproteins; D008024:Ligands; D008565:Membrane Proteins; D011971:Receptors, Immunologic; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051117:Scavenger Receptors, Class A; D051122:Scavenger Receptors, Class B; D003094:Collagen