title: Amyotrophic lateral sclerosis-associated proteins TDP-43 and FUS/TLS function in a common biochemical complex to co-regulate HDAC6 mRNA.
abstract: Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease that preferentially targets motor neurons. It was recently found that dominant mutations in two related RNA-binding proteins, TDP-43 (43-kDa TAR DNA-binding domain protein) and FUS/TLS (fused in sarcoma/translated in liposarcoma) cause a subset of ALS. The convergent ALS phenotypes associated with TDP-43 and FUS/TLS mutations are suggestive of a functional relationship; however, whether or not TDP-43 and FUS/TLS operate in common biochemical pathways is not known. Here we show that TDP-43 and FUS/TLS directly interact to form a complex at endogenous expression levels in mammalian cells. Binding was mediated by an unstructured TDP-43 C-terminal domain and occurred within the context of a 300-400-kDa complex that also contained C-terminal cleavage products of TDP-43 linked to neuropathology. TDP-43 C-terminal fragments were excluded from large molecular mass TDP-43 ribonucleoprotein complexes but retained FUS/TLS binding activity. The functional significance of TDP-43-FUS/TLS complexes was established by showing that RNAi silencing of either TDP-43 or FUS/TLS reduced the expression of histone deacetylase (HDAC) 6 mRNA. TDP-43 and FUS/TLS associated with HDAC6 mRNA in intact cells and in vitro, and competition experiments suggested that the proteins occupy overlapping binding sites. The combined findings demonstrate that TDP-43 and FUS/TLS form a functional complex in intact cells and suggest that convergent ALS phenotypes associated with TDP-43 and FUS/TLS mutations may reflect their participation in common biochemical processes.
authors: Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53706, USA.
authors: Sang Hwa
authors: SH
authors: Kim
authors: Naval P
authors: NP
authors: Shanware
authors: Michael J
authors: MJ
authors: Bowler
authors: Randal S
authors: RS
authors: Tibbetts
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000378:metabolism*; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000737:chemistry*; D005786:Gene Expression Regulation; D006367:HeLa Cells; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases / Q000737:chemistry*; D006801:Humans; D009046:Motor Neurons / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D025941:Protein Interaction Mapping; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034702:RNA-Binding Protein FUS / Q000737:chemistry*; D016601:RNA-Binding Proteins / Q000737:chemistry
chemical_list: D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D034702:RNA-Binding Protein FUS; D016601:RNA-Binding Proteins; C433811:HDAC6 protein, human; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases