The developmental protein Numb is a major determinant of binary cell fates(1-3). It is also required for the differentiation of cerebellar granule cell progenitors (GCPs)(4) at a stage of development responsive to the morphogenic glycoprotein Hedehog(5,6). Hedgehog signalling is crucial for the physiological maintenance and self-renewal of neural stem cells and its deregulation is responsible for their progression towards tumorigenesis(5,7-11). The mechanisms that inhibit this pathway during the differentiation stage are poorly understood. Here, we identify Numb as a Hedgehog-pathway inhibitor that is downregulated in early GCPs and GCP-derived cancer cells. We demonstrate that the Hedgehog transcription factor Gli1 is targeted by Numb for Itch-dependent ubiquitination, which suppresses Hedgehog signals, thus arresting growth and promoting cell differentiation. This novel Numb-dependent regulatory loop may limit the extent and duration of Hedgehog signalling during neural-progenitor differentiation, and its subversion may be a relevant event in brain tumorigenesis.

Numb is a suppressor of Hedgehog signaling and targets Gli1 for Itch-dependent ubiquitination / DI MARCOTULLIO, L; Ferretti, Elisabetta; Greco, A; DE SMAELE, Enrico; Po, Agnese; Alimandi, Maurizio; Giannini, G; Maroder, M; Screpanti, I; AND GULINO, A.. - ELETTRONICO. - (2006). (Intervento presentato al convegno EMBO Workshop Hedgehog-Gli signaling in cancer and stem cells tenutosi a Roma).

Numb is a suppressor of Hedgehog signaling and targets Gli1 for Itch-dependent ubiquitination.

FERRETTI, ELISABETTA;DE SMAELE, Enrico;PO, AGNESE;ALIMANDI, MAURIZIO;GIANNINI G;SCREPANTI I;
2006

Abstract

The developmental protein Numb is a major determinant of binary cell fates(1-3). It is also required for the differentiation of cerebellar granule cell progenitors (GCPs)(4) at a stage of development responsive to the morphogenic glycoprotein Hedehog(5,6). Hedgehog signalling is crucial for the physiological maintenance and self-renewal of neural stem cells and its deregulation is responsible for their progression towards tumorigenesis(5,7-11). The mechanisms that inhibit this pathway during the differentiation stage are poorly understood. Here, we identify Numb as a Hedgehog-pathway inhibitor that is downregulated in early GCPs and GCP-derived cancer cells. We demonstrate that the Hedgehog transcription factor Gli1 is targeted by Numb for Itch-dependent ubiquitination, which suppresses Hedgehog signals, thus arresting growth and promoting cell differentiation. This novel Numb-dependent regulatory loop may limit the extent and duration of Hedgehog signalling during neural-progenitor differentiation, and its subversion may be a relevant event in brain tumorigenesis.
2006
EMBO Workshop Hedgehog-Gli signaling in cancer and stem cells
PROGENITOR-CELL MAINTENANCE; SONIC HEDGEHOG; INTRACELLULAR DOMAIN;
04 Pubblicazione in atti di convegno::04b Atto di convegno in volume
Numb is a suppressor of Hedgehog signaling and targets Gli1 for Itch-dependent ubiquitination / DI MARCOTULLIO, L; Ferretti, Elisabetta; Greco, A; DE SMAELE, Enrico; Po, Agnese; Alimandi, Maurizio; Giannini, G; Maroder, M; Screpanti, I; AND GULINO, A.. - ELETTRONICO. - (2006). (Intervento presentato al convegno EMBO Workshop Hedgehog-Gli signaling in cancer and stem cells tenutosi a Roma).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/55677
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