The EGF-TM7 family: a postgenomic view.
With the human and mouse genome projects now completed, the receptor repertoire of mammalian cells has finally been elucidated. The EGF-TM7 receptors are a family of class B seven-span transmembrane (TM7) receptors predominantly expressed by cells of the immune system. Within the large TM7 superfamily, the molecular structure and ligand-binding properties of EGF-TM7 receptors are unique. Derived from the processing of a single polypeptide, they are expressed at the cell surface as heterodimers consisting of a large extracellular region associated with a TM7 moiety. Through a variable number of N-terminal epidermal growth factor (EGF)-like domains, EGF-TM7 receptors interact with cellular ligands such as CD55 and chondroitin sulfate. Recent in vivo studies demonstrate a role of the EGF-TM7 receptor CD97 in leukocyte migration. The different number of EGF-TM7 genes in man compared with mice, the chimeric nature of EMR2 and the inactivation of human EMR4 point toward a still-evolving receptor family. Here we discuss the currently available information on this intriguing receptor family.
Kwakkenbos
Mark J
MJ
Laboratory for Experimental Immunology, Academic Medical Center, University of Amsterdam, G1-106, PO Box 22700, 1100 DE, Amsterdam, The Netherlands.
Kop
Else N
EN
Stacey
Martin
M
Matmati
Mourad
M
Gordon
Siamon
S
Lin
Hsi-Hsien
HH
Hamann
Jörg
J
D000595:Amino Acid Sequence; D000818:Animals; D002465:Cell Movement; D004815:Epidermal Growth Factor / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D019143:Evolution, Molecular; D019204:GTP-Binding Proteins / Q000502:physiology; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000502:physiology; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism; D022423:Myeloid Cells / Q000378:metabolism; D011323:Primates / Q000235:genetics; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D043562:Receptors, G-Protein-Coupled / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013045:Species Specificity
C483023:ADGRE4P protein, human; C464944:Emr4 protein, mouse; D008565:Membrane Proteins; D043562:Receptors, G-Protein-Coupled; D004815:Epidermal Growth Factor; D019204:GTP-Binding Proteins