Abstract

Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by loss of motor neurons in patients with null mutations in the SMN1 gene. An almost identical SMN2 gene is unable to compensate for this deficiency because a single C-to-T transition at position +6 in exon-7 causes skipping of the exon by a mechanism not yet fully elucidated. We observed that the C-to-T transition in SMN2 creates a putative binding site for the RNA-binding protein Sam68. RNA pull-down assays and UV-crosslink experiments showed that Sam68 binds to this sequence. In vivo splicing assays showed that Sam68 triggers SMN2 exon-7 skipping. Moreover, mutations in the Sam68-binding site of SMN2 or in the RNA-binding domain of Sam68 completely abrogated its effect on exon-7 skipping. Retroviral infection of dominant-negative mutants of Sam68 that interfere with its RNA-binding activity, or with its binding to the splicing repressor hnRNP A1, enhanced exon-7 inclusion in endogenous SMN2 and rescued SMN protein expression in fibroblasts of SMA patients. Our results thus indicate that Sam68 is a novel crucial regulator of SMN2 splicing.

Autore Pugliese

• Fimia Gian Maria

Tutti gli autori

• Pedrotti S. , Bielli P. , Paronetto M.P. , Ciccosanti F. , Fimia G.M. , Stamm S. , Manley J.L. , Sette C.

Titolo volume/Rivista

EMBO JOURNAL

Anno di pubblicazione

2010

ISSN

1460-2075

ISBN

Non Disponibile

Numero di citazioni Wos

73

Ultimo Aggiornamento Citazioni

25/04/2018

Numero di citazioni Scopus

74

Ultimo Aggiornamento Citazioni

26/04/2018

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile