THE QUAKING GENE-PRODUCT NECESSARY IN EMBRYOGENESIS AND MYELINATION COMBINES FEATURES OF RNA-BINDING AND SIGNAL-TRANSDUCTION PROTEINS

The mouse quaking gene, essential for nervous system myelination and s urvival of the early embryo has been positionally cloned. Its sequence implies that the locus encodes a multifunctional gene used in a speci fic set of developing tissues to unite signal transduction with some a spect of RNA metabolism. The quaking(viable) (qk(v)) mutation has one class of messages truncated by a deletion. An independent ENU-induced mutation has a nonconservative amino acid change in one of two newly i dentified domains that are conserved from the C. elegans gld-1 tumour suppressor gene to the human Src-associated protein Sam68. The size an d conservation of the quaking gene family implies that the pathway def ined by this mutation may have broad relevance for rapid conveyance of extracellular information directly to primary gene transcripts.