4blb
Crystal structure of a human Suppressor of fused (SUFU)-GLI1p complex
Structural highlights
DiseaseSUFU_HUMAN Defects in SUFU are a cause of medulloblastoma (MDB) [MIM:155255. MDB is a malignant, invasive embryonal tumor of the cerebellum with a preferential manifestation in children. Defects in SUFU play a role in predisposition to desmoplastic MDB. These tumors make up about 20 to 30% of medulloblastomas, have a more nodular architecture than 'classical' medulloblastoma, and may have a better prognosis. FunctionMALE_ECOLI Involved in the high-affinity maltose membrane transport system MalEFGK. Initial receptor for the active transport of and chemotaxis toward maltooligosaccharides.SUFU_HUMAN Negative regulator in the hedgehog signaling pathway. Down-regulates GLI1-mediated transactivation of target genes. Part of a corepressor complex that acts on DNA-bound GLI1. May also act by linking GLI1 to BTRC and thereby targeting GLI1 to degradation by the proteasome. Sequesters GLI1, GLI2 and GLI3 in the cytoplasm, this effect is overcome by binding of STK36 to both SUFU and a GLI protein. Negative regulator of beta-catenin signaling. Regulates the formation of either the repressor form (GLI3R) or the activator form (GLI3A) of the full length form of GLI3 (GLI3FL). GLI3FL is complexed with SUFU in the cytoplasm and is maintained in a neutral state. Without the Hh signal, the SUFU-GLI3 complex is recruited to cilia, leading to the efficient processing of GLI3FL into GLI3R. When Hh signaling is initiated, SUFU dissociates from GLI3FL and the latter translocates to the nucleus, where it is phosphorylated, destabilized, and converted to a transcriptional activator (GLI3A).[1] [2] [3] [4] [5] Publication Abstract from PubMedHedgehog signalling plays a fundamental role in the control of metazoan development, cell proliferation and differentiation, as highlighted by the fact that its deregulation is associated with the development of many human tumours. SUFU is an essential intracellular negative regulator of mammalian Hedgehog signalling and acts by binding and modulating the activity of GLI transcription factors. Despite its central importance, little is known about SUFU regulation and the nature of SUFU-GLI interaction. Here, the crystal and small-angle X-ray scattering structures of full-length human SUFU and its complex with the key SYGHL motif conserved in all GLIs are reported. It is demonstrated that GLI binding is associated with major conformational changes in SUFU, including an intrinsically disordered loop that is also crucial for pathway activation. These findings reveal the structure of the SUFU-GLI interface and suggest a mechanism for an essential regulatory step in Hedgehog signalling, offering possibilities for the development of novel pathway modulators and therapeutics. Structural basis of SUFU-GLI interaction in human Hedgehog signalling regulation.,Cherry AL, Finta C, Karlstrom M, Jin Q, Schwend T, Astorga-Wells J, Zubarev RA, Del Campo M, Criswell AR, de Sanctis D, Jovine L, Toftgard R Acta Crystallogr D Biol Crystallogr. 2013 Dec;69(Pt 12):2563-79. doi:, 10.1107/S0907444913028473. Epub 2013 Nov 19. PMID:24311597[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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