High impact information on Gpc4

• Hepatocyte growth factor-mediated renal epithelial branching morphogenesis is regulated by glypican-4 expression [1].
• We have functionally analysed the role of Xenopus Gpc4 by using antisense morpholino oligonucleotides and show that Gpc4 is part of the signalling network that patterns the forebrain [2].
• Glypican-4 expression is not detected in the midline of the embryo at the stage of initiation of neural tube closure, suggesting that glypican-4 is unlikely to play an essential role in convergent extension in the mouse [3].
• Analysis by in situ hybridization reveals a complex pattern of glypican-4 mRNA localization at embryonic days 7-10.5, including sites in the anterior forebrain neuroepithelium, branchial arches, optic and otic vesicles, limb buds and somites [3].
• Syndecan-1 and glypican-4 were the most highly expressed in the developing brain during the time of peak proliferation and localise to ventricular regions of the brain, where the precursor cells are proliferating [4].

Biological context of Gpc4

• The Gpc4 gene consists of nine exons separated by eight introns [5].
• Transactivation experiments in insect cells showed that both Sp1 and Sp3 are major activators of the Gpc4 promoter [5].
• Mouse K-glypican gene, gpc4, maps to chromosome X [6].
• Comparison of RNA fingerprinting of the avian eggshell gland (ESG) without and with an egg revealed upregulation of a 382-bp cDNA fragment that showed high homology to the mammalian glypican 4 (GPC-4) [7].
• Mechanical strain regulation of the chicken glypican-4 gene expression in the avian eggshell gland [7].

Anatomical context of Gpc4

• Gpc4 is expressed in adipocytes where its expression is highest in confluent 3T3-F442A adipoblasts and decreases dramatically as cells differentiate [5].

Other interactions of Gpc4

• Mice carrying the high-growth QTL allele have approximately 15% lower Gpc3 mRNA expression in kidney and liver, whereas expression differences at Gpc4 are non-significant [8].

References