R. S. Winning

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Pagliaccio (Pag) is a receptor tyrosine kinase of the Eph family that is expressed in Xenopus embryos in a diverse set of localized tissues. Pag is the Xenopus homolog of Hek-8 (human), Sek-1 (mouse), cek8 (chicken), and RTK-1 (zebrafish). We have investigated the function of this protein by injecting RNA encoding an epidermal growth factor receptor-Pag(More)
Cranial neural crest cells arise from neural folds in the embryonic head and differentiate to produce most of the cartilages and bones of the skull and the somatosensory ganglia of several cranial nerves, among other tissues. Since the molecular basis of the determination of these cells is poorly understood, we have begun a search for molecules involved in(More)
We have isolated a cDNA clone encoding the Xenopus homologue of the transcription factor AP-2 (XAP-2). The predicted amino acid sequence derived from the Xenopus cDNA shows very strong conservation with the amino acid sequence of human AP-2, suggesting that this protein is evolutionarily conserved, at least among vertebrates. This is further substantiated(More)
Three cDNAs encoding receptor tyrosine kinases (RTKs) of the eph-subfamily have been identified based on their homology to Pagliaccio (Winning and Sargent, 1994, Mech. Dev. 46:219-229). These have been named TCK, Xelk (Xenopus homologue of elk), and PL7a (pag-like clone 7a). Each of these genes is expressed in a distinctive, tissue specific manner during(More)
The Eph family of receptor tyrosine kinases is involved in limiting cell and tissue interactions via a repulsive mechanism. The mechanism of repulsion involves reorganizing the actin cytoskeleton, but little is known of the molecular components that connect the receptor to the actin cytoskeleton. Recent studies in retinal ganglion cells have demonstrated(More)
This paper identifies a new, developmental role for transcription factor AP-2 in the activation of amphibian embryonic epidermal keratin gene expression. Keratin transcription factor KTF-1 is shown by several criteria to be identical or closely related to AP-2. KTF-1/AP-2 is shown to be tissue-specific from its first transcription in Xenopus embryos, and(More)
Developmental regulation of the expression of a glucose-regulated gene encoding a 78 kd protein, GRP78, has been characterized by microinjection of a rat GRP78/CAT chimeric gene into early Xenopus embryos. Tunicamycin-induced expression of the chimeric gene during Xenopus development was similar to the pattern of endogenous GRP78 protein synthesis, with(More)
Bidirectional signaling between Eph receptor tyrosine kinases and their cell-surface protein signals, the ephrins, comprises one mechanism for guiding motor axons to their proper targets. During projection of motor axons from the lateral motor column (LMC) motor neurons of the spinal cord to the hindlimb muscles in chick embryos, ephrin-A5 has been shown to(More)
The Eph family of receptor tyrosine kinases and their ephrin ligands are believed to limit cell-cell interactions during embryonic development via a repulsive mechanism. Little is known, however, about the intracellular effects of Eph signaling that lead to cellular repulsion. We have used scanning and transmission electron microscopy to examine the effects(More)
We have characterized the induction of glucose-regulated proteins (GRPs) in Xenopus laevis A6 cells, a kidney epithelial cell line. Exposure of A6 cells to medium in which 2-deoxyglucose replaced galactose resulted in enhanced synthesis of two proteins at 78 and 98 kd. The 78 kd protein was determined by two-dimensional PAGE to consist of two isoelectric(More)