A novel class of murine semaphorins with homology to thrombospondin is differentially expressed during early embryogenesis.
The semaphorins are a family of proteins thought to be involved in axonal guidance. Most of the known semaphorins have a similar primary structure characterized by the semaphorin domain and a carboxy-terminal Ig motif. Here we report the cloning of two members (semF and G) of a novel class of membrane-bound semaphorins which contain seven carboxy-terminal thrombospondin repeats, a motif known to promote neurite outgrowth. SemF and G transcripts are expressed, together with semD and E, in specific regions of young mouse embryos, demarcating distinct compartments of the developing somites or the undifferentiated neuroepithelium. The identification of semF and G increases the number of vertebrate semaphorins to at least 20 and suggests that some semaphorins might act as positive axonal guidance cues.
Adams
R H
RH
Abteilung Neurochemie, Max-Planck-Institut für Hirnforschung, Frankfurt/Main, Germany.
Betz
H
H
Püschel
A W
AW
D000367:Age Factors; D000595:Amino Acid Sequence; D000818:Animals; D001369:Axons / Q000502:physiology; D003001:Cloning, Molecular; D004622:Embryo, Mammalian; D018507:Gene Expression Regulation, Developmental; D006023:Glycoproteins / Q000096:biosynthesis* / Q000145:classification / Q000235:genetics*; D018878:Limb Buds / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000737:chemistry; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D009432:Neural Crest / Q000502:physiology; D040121:Semaphorin-3A; D039961:Semaphorins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019699:Thrombospondins; D014018:Tissue Distribution
D006023:Glycoproteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C103150:Sema4d protein, mouse; C103619:Sema5A protein, mouse; D040121:Semaphorin-3A; D039961:Semaphorins; D019699:Thrombospondins