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Tham khảo luận văn - đề án 'báo cáo y học: "the electronic version of this article is the complete one and can be found online"', luận văn - báo cáo phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Protein family review Glypicans Jorge Filmus Mariana Capurro and Jonathan Rast Address Division of Molecular and Cellular Biology Sunnybrook Health Sciences Centre and Department of Medical Biophysics University of Toronto Toronto Ontario M4N 3M5 Canada. Correspondence Jorge Filmus. E-mail Jorge.filmus@sri.utoronto.ca Published 22 May 2008 GenomeBiology 2008 9 224 doi 10.1186 gb-2008-9-5-224 The electronic version of this article is the complete one and can be found online at http genomebiology.com 2008 9 5 224 2008 BioMed Central Ltd Summary Glypicans are heparan sulfate proteoglycans that are bound to the outer surface of the plasma membrane by a glycosyl-phosphatidylinositol anchor. Homologs of glypicans are found throughout the Eumetazoa. There are six family members in mammals GPC1 to GPC6 . Glypicans can be released from the cell surface by a lipase called Notum and most of them are subjected to endoproteolytic cleavage by furin-like convertases. In vivo evidence published so far indicates that the main function of membrane-attached glypicans is to regulate the signaling of Wnts Hedgehogs fibroblast growth factors and bone morphogenetic proteins BMPs . Depending on the context glypicans may have a stimulatory or inhibitory activity on signaling. In the case of Wnt it has been proposed that the stimulatory mechanism is based on the ability of glypicans to facilitate and or stabilize the interaction of Wnts with their signaling receptors the Frizzled proteins. On the other hand GPC3 has recently been reported to inhibit Hedgehog protein signaling during development by competing with Patched the Hedgehog receptor for Hedgehog binding. Surprisingly the regulatory activity of glypicans in the Wnt Hedgehog and BMP signaling pathways is only partially dependent on the heparan sulfate chains. Gene organization and evolutionary history Glypicans are heparan sulfate proteoglycans that are bound to the external surface of the plasma membrane by a .
