Embryology Research Today is a free monthly online journal that collates and summarizes the latest research about Embryology, including details on stem cells, reproduction, transplants, cloning.

The secreted serine protease xHtrA1 stimulates long-range FGF signaling in the early Xenopus embryo.

Hou S, Maccarana M, Min TH, Strate I, Pera EM

Department of Developmental Biochemistry, Institute of Biochemistry and Cell Biology, Georg August University Göttingen, 37077 Göttingen, Germany.

We found that the secreted serine protease xHtrA1, expressed in the early embryo and transcriptionally activated by FGF signals, promotes posterior development in mRNA-injected Xenopus embryos. xHtrA1 mRNA led to the induction of secondary tail-like structures, expansion of mesoderm, and formation of ectopic neurons in an FGF-dependent manner. An antisense morpholino oligonucleotide or a neutralizing antibody against xHtrA1 had the opposite effects. xHtrA1 activates FGF/ERK signaling and the transcription of FGF genes. We show that Xenopus Biglycan, Syndecan-4, and Glypican-4 are proteolytic targets of xHtrA1 and that heparan sulfate and dermatan sulfate trigger posteriorization, mesoderm induction, and neuronal differentiation via the FGF signaling pathway. The results are consistent with a mechanism by which xHtrA1, through cleaving proteoglycans, releases cell-surface-bound FGF ligands and stimulates long-range FGF signaling.

Published 7 August 2007 in Dev Cell, 13(2): 226-41.
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