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Motta M, Giancotti A, Mastromoro G, Chandramouli B, Pinna V, Pantaleoni F, Di Giosaffatte N, Petrini S, Mazza T, D'Ambrosio V, Versacci P, Ventriglia F, Chillemi G, Pizzuti A, Tartaglia M, De Luca A. Clinical and functional characterization of a novel RASopathy-causing SHOC2 mutation associated with prenatal-onset hypertrophic cardiomyopathy. Hum Mutat 2019; 40:1046-1056. [PMID: 31059601 DOI: 10.1002/humu.23767] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/26/2019] [Accepted: 04/17/2019] [Indexed: 12/17/2022]
Abstract
SHOC2 is a scaffold protein mediating RAS-promoted activation of mitogen-activated protein kinase (MAPK) signaling in response to extracellular stimuli. A recurrent activating mutation in SHOC2 (p.Ser2Gly) causes Mazzanti syndrome, a RASopathy characterized by features resembling Noonan syndrome and distinctive ectodermal abnormalities. A second mutation (p.Met173Ile) supposed to cause loss-of-function was more recently identified in two individuals with milder phenotypes. Here, we report on the third RASopathy-causing SHOC2 mutation (c.807_808delinsTT, p.Gln269_His270delinsHisTyr), which was found associated with prenatal-onset hypertrophic cardiomyopathy. Structural analyses indicated a possible impact of the mutation on the relative orientation of the two SHOC2's leucine-rich repeat domains. Functional studies provided evidence of its activating role, revealing enhanced binding of the mutant protein to MRAS and PPP1CB, and increased signaling through the MAPK cascade. Differing from SHOC2 S2G , SHOC2 Q269_H270delinsHY is not constitutively targeted to the plasma membrane. These data document that diverse mechanisms in SHOC2 functional dysregulation converge toward MAPK signaling upregulation.
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Affiliation(s)
- Marialetizia Motta
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Antonella Giancotti
- Department of Maternal and Child Health and Urologic Science, Policlinico Umberto I Hospital, "Sapienza" University, Rome, Italy
| | - Gioia Mastromoro
- Department of Experimental Medicine, "Sapienza" University, Rome, Italy
| | | | - Valentina Pinna
- Molecular Genetics Unit, Fondazione Casa Sollievo della Sofferenza, IRCCS, San Giovanni Rotondo, Italy
| | - Francesca Pantaleoni
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Niccolò Di Giosaffatte
- Molecular Genetics Unit, Fondazione Casa Sollievo della Sofferenza, IRCCS, San Giovanni Rotondo, Italy
| | - Stefania Petrini
- Confocal Microscopy Core Facility, Research Laboratories, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Tommaso Mazza
- Bioinformatics Unit, Fondazione Casa Sollievo della Sofferenza, IRCCS, San Giovanni Rotondo, Italy
| | - Valentina D'Ambrosio
- Department of Maternal and Child Health and Urologic Science, Policlinico Umberto I Hospital, "Sapienza" University, Rome, Italy
| | - Paolo Versacci
- Department of Pediatrics, Università Sapienza, Rome, Italy
| | | | | | - Antonio Pizzuti
- Department of Experimental Medicine, "Sapienza" University, Rome, Italy
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Alessandro De Luca
- Molecular Genetics Unit, Fondazione Casa Sollievo della Sofferenza, IRCCS, San Giovanni Rotondo, Italy
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