title: Twist is substrate for caspase cleavage and proteasome-mediated degradation.
abstract: Twist is a member of the basic helix-loop-helix family of transcription factors. An aberrant Twist expression has been found in diverse types of cancer, including sarcomas, carcinomas and lymphomas, supporting a role for Twist in tumor progression. Twist is known to be essential for mesodermal development. However, since a prolonged Twist expression results in a block of muscle, cartilage and bone differentiation, Twist has to be excluded from somites during late embryogenesis for terminal differentiation to occur. This implies that Twist expression must be target of a tight control. Here we provide evidence that Twist undergoes post-transcriptional regulation. Twist is substrate for cleavage by caspases during apoptosis and its cleavage results in ubiquitin-mediated proteasome degradation. Our findings suggest that Twist post-transcriptional regulation may play an important role in tissue determination and raise the possibility that alterations in the protein turnover may account for Twist overexpression observed in tumors.
authors.affiliation: Unit of Molecular Mechanisms of Neoplastic Progression, Department of Experimental Oncology, CRO IRCCS National Cancer Institute, Aviano, PN, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Demontis
authors.forename: C
authors.initials: C
authors.lastname: Rigo
authors.forename: S
authors.initials: S
authors.lastname: Piccinin
authors.forename: M
authors.initials: M
authors.lastname: Mizzau
authors.forename: M
authors.initials: M
authors.lastname: Sonego
authors.forename: M
authors.initials: M
authors.lastname: Fabris
authors.forename: C
authors.initials: C
authors.lastname: Brancolini
authors.forename: R
authors.initials: R
authors.lastname: Maestro
mesh_terms: D000818:Animals; D017209:Apoptosis; D015152:Blotting, Northern; D020170:Caspase 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D018450:Disease Progression; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D046988:Proteasome Endopeptidase Complex / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D051879:Twist-Related Protein 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism
chemical_list: D051879:Twist-Related Protein 1; D025801:Ubiquitin; D020170:Caspase 1; D046988:Proteasome Endopeptidase Complex