title: Expansion of the complement receptor gene family. Identification in the mouse of two new genes related to the CR1 and CR2 gene family.
abstract: Human cDNA probes encoding the C3b/C4b complement receptor, CR1, have been used to identify, in the mouse, two new genes which are related to CR1 but which appear to encode a different protein product. These new mouse genes, arbitrarily designated mouse genes X and Y, hybridize specifically to three different cDNA probes derived from human CR1. The degree of hybridization homology between the mouse X and Y genes suggests they are very closely related to one another; however, the chromosomal localization of the mouse X gene to chromosome 8 and the mouse Y gene to chromosome 1 indicates they are distinct gene sequences. The mRNA species detected with the X and/or Y (X/Y) sequences are approximately 2000 bases in length, but vary in both quantity and size depending upon the tissue analyzed. DNA sequence analysis of a cDNA specific for the X and Y sequences indicates the mature protein(s) will contain the 60 amino acid consensus repeat characteristic of a group of other proteins including CR1, the C3d receptor (CR2), H, C4 binding protein (C4bp), the interleukin 2 (Il 2) receptor and others. The identity of the mouse X and Y genes, and the function of the proteins which they encode, is not known; however, the small size of the mRNA and the tissue specific expression suggests they do not encode mouse CR1 or CR2 but instead encode a related protein (or proteins) which is expressed in a wide variety of mouse tissues.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004247:DNA / Q000235:genetics; D005796:Genes; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C / Q000235:genetics* / Q000276:immunology; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000235:genetics; D011951:Receptors, Complement / Q000235:genetics*; D017463:Receptors, Complement 3b; D017464:Receptors, Complement 3d; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D012333:RNA, Messenger; D011951:Receptors, Complement; D017463:Receptors, Complement 3b; D017464:Receptors, Complement 3d; D004247:DNA