Titre : | Interactions of the M-line titin domain M10, mutated in TMD/LGMD2J (abstract : congrès international de Myologie, 2005) |
contenu dans : | |
Auteurs : | Congrès international de myologie 2005 (International Congress of Myology 2005; 9-13 mai 2005; Nantes, France) ; Sarparanta J ; Vihola A ; Hackman P ; Udd B |
Type de document : | Article |
Année de publication : | 2005 |
Pages : | p. 91 |
Langues: | Anglais |
Mots-clés : | Belgique ; colloque ; France ; LGMDR10 liée à la titine ; muscle squelettique ; mutation génétique ; myopathie distale de type Udd ; sarcomère ; titine |
Résumé : |
Communication n° 351. Introduction : Mutations in the exon Mex6, encoding the C-terminal domain M10 of titin, cause two separate muscle disease phenotypes. Tibial muscular dystrophy (TMD) is a dominant late onset distal myopathy. Finnish TMD patients carry an insertion/deletion mutation causing an exchange of 4 amino acids in the M10 domain. In a homozygous state, the same mutation causes severe early onset limb-girdle muscular dystrophy type 2J (LGMD2J). In French and Belgian families, TMD is caused by two separate point mutations in the same exon. The mutations are predicted to cause misfolding of the Ig-like domain M10 situated in the M-line of the sarcomere. Objectives : Apart from the recently identified KY protein, no ligands are known for the titin M10 domain. Our aim was to search for specific M10 domain ligands in order to identify disrupted interactions involved in the pathogenesis of the diseases. Methods : An interaction screen against a human skeletal muscle cDNA library in pACT2 (Clontech) was performed at the yeast two-hybrid core facility of Biocentrum Helsinki. A pGBKT7 construct encoding the 132 last amino acid residues of the titin Mex5- isoform was used as bait. Results : The screen yielded 84 positive clones, which coded for 21 different proteins in correct frame. Phosphoglucomutase 1, metallothionein 2A, ring finger protein 1, cardiomyopathy-associated 5, kinectin 1, RAN binding protein 9 and titin itself were among the proteins encoded by several clones. The putative interactions are currently evaluated and the effects of the disease mutations investigated by additional yeast and mammalian two-hybrid studies and protein chemical methods. Conclusions : As the interactions of the titin M10 domain are likely to be affected by the TMD/LGMD2J mutations, the ligands identified here may be important in the pathogenesis of the diseases. Further conclusions will be reported along with results from the ongoing experiments to validate the interactions with wild type and mutant titin. |