Project description:FUS/TLS is an RNA/DNA-binding protein associated with neurodegenerative diseases including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Previously, we found that a prion-like domain in the N-terminus of FUS/TLS mediates co-aggregation between FUS/TLS and mutant huntingtin, the gene product of Huntington's disease (HD). Here, we show that heterozygous knockout of FUS/TLS worsened the phenotypes of model mice of Huntington's disease (HD) but not spinal and bulbar muscular atrophy (SBMA). This difference was correlated with the degree of pathological association between disease proteins and FUS/TLS. Co-aggregation between FUS/TLS and mutant huntingtin resulted in the depletion of free FUS/TLS protein in HD mice that was detected as a monomer in SDS-PAGE analysis. Recently, we found that FUS/TLS paralogs, TAF15 and EWS, were up-regulated in homozygous FUS/TLS knockout mice. These two proteins were up-regulated in both HD and FUS/TLS heterozygote mice, and were further elevated in HD-TLS+/- double mutant mice, consistent with the functional impairment of FUS/TLS. These results suggest that FUS/TLS sequestration by co-aggregation is a rate-limiting factor of disease phenotypes of HD and that inclusions may have an adverse aspect, rather than being simply benign or protective. In addition, our results highlight inclusions as repositories of potential modifiers of neurodegeneration. Gene expression profiles were analyzed to examine the effects of FUS/TLS heterozygosity in mouse with or without the transgene of mutant androgen receptor.
Project description:FUS/TLS is an RNA/DNA-binding protein associated with neurodegenerative diseases including amyotrophic lateral sclerosis and frontotemporal lobar degeneration. Previously, we found that a prion-like domain in the N-terminus of FUS/TLS mediates co-aggregation between FUS/TLS and mutant huntingtin, the gene product of Huntington's disease (HD). Here, we show that heterozygous knockout of FUS/TLS worsened the phenotypes of model mice of Huntington's disease (HD) but not spinal and bulbar muscular atrophy (SBMA). This difference was correlated with the degree of pathological association between disease proteins and FUS/TLS. Co-aggregation between FUS/TLS and mutant huntingtin resulted in the depletion of free FUS/TLS protein in HD mice that was detected as a monomer in SDS-PAGE analysis. Recently, we found that FUS/TLS paralogs, TAF15 and EWS, were up-regulated in homozygous FUS/TLS knockout mice. These two proteins were up-regulated in both HD and FUS/TLS heterozygote mice, and were further elevated in HD-TLS+/- double mutant mice, consistent with the functional impairment of FUS/TLS. These results suggest that FUS/TLS sequestration by co-aggregation is a rate-limiting factor of disease phenotypes of HD and that inclusions may have an adverse aspect, rather than being simply benign or protective. In addition, our results highlight inclusions as repositories of potential modifiers of neurodegeneration. Gene expression profiles were analyzed to examine the effects of FUS/TLS heterozygosity in mouse with or without the transgene of mutant huntingtin exon 1.
Project description:The RNA-binding protein FUS/TLS, mutation in which is causative of the fatal motor neuron disease ALS, is demonstrated to directly bind to the U1-snRNP and SMN complexes. ALS-causative mutations in FUS/TLS are shown to abnormally enhance their interaction with SMN and reduce interaction with U1-snRNP. Correspondingly, global RNA analysis reveals a mutant-dependent loss of splicing activity, with ALS-linked mutants failing to reverse changes caused by loss of wild-type FUS/TLS. Furthermore, a common FUS/TLS mutant-associated RNA splicing signature is identified in ALS patient fibroblasts. Taken together, our studies establish potentially converging disease mechanisms in ALS and spinal muscular atrophy, with ALS-causative mutants acquiring properties representing both gain (dysregulation of SMN) and loss (reduced RNA processing mediated by U1-snRNP) of function. RNA-mediated oligonucleotide Annealing, Selection, and Ligation with Next-Generation sequencing (RASL-seq) method was used for analyzing alternative splicing changes. Oligonucleotide probes are designed to anneal to the exon-exon junctions. The probe library was assembled to assess 5530 unique alternative splicing events, most of which were exon inclusion or skipping, with a minority for alternative 5’- or 3’- splice sites. The splicing changes were compared among groups of reducing FUS/TLS or SMN levels, or expressing various FUS mutations to determine the loss versus gain of FUS/TLS function on splicing regulation.
Project description:The RNA-binding protein FUS/TLS, mutation in which is causative of the fatal motor neuron disease ALS, is demonstrated to directly bind to the U1-snRNP and SMN complexes. ALS-causative mutations in FUS/TLS are shown to abnormally enhance their interaction with SMN and reduce interaction with U1-snRNP. Correspondingly, global RNA analysis reveals a mutant-dependent loss of splicing activity, with ALS-linked mutants failing to reverse changes caused by loss of wild-type FUS/TLS. Furthermore, a common FUS/TLS mutant-associated RNA splicing signature is identified in ALS patient fibroblasts. Taken together, our studies establish potentially converging disease mechanisms in ALS and spinal muscular atrophy, with ALS-causative mutants acquiring properties representing both gain (dysregulation of SMN) and loss (reduced RNA processing mediated by U1-snRNP) of function.
Project description:FUS/TLS and TDP-43 are RNA/DNA-binding proteins integrally involved in amyotrophic lateral sclerosis (ALS) and frontal temporal dementia. FUS/TLS is shown to bind RNAs from >5,500 genes in mouse and human brain, primarily through a GUGGU binding motif. A characteristic sawtooth-like binding pattern is identified, supporting co-transcriptional deposition of FUS/TLS. Depletion of FUS/TLS from the adult nervous system is shown to alter levels or splicing of >970 mRNAs, most of which are distinct from the RNAs whose maturation is dependent on TDP-43. Nonetheless, only 55 RNAs are reduced upon depletion of either TDP-43 or FUS/TLS from mouse brain and human neurons differentiated from pluripotent stem cells, including mRNAs transcribed from genes with exceptionally long introns and that encode proteins essential for neuronal integrity. A subset of these is significantly lowered in FUS/TLSR521G and TDP-43G298S mutant fibroblasts and in TDP-43 aggregate-containing motor neurons in sporadic ALS, evidence pointing to a common loss-of-function pathway as one component underlying motor neuron death from misregulation of TDP-43 or FUS/TLS. Microarray of Fus/Tls in 8 week mouse brain
Project description:FUS/TLS and TDP-43 are RNA/DNA-binding proteins integrally involved in amyotrophic lateral sclerosis (ALS) and frontal temporal dementia. FUS/TLS is shown to bind RNAs from >5,500 genes in mouse and human brain, primarily through a GUGGU binding motif. A characteristic sawtooth-like binding pattern is identified, supporting co-transcriptional deposition of FUS/TLS. Depletion of FUS/TLS from the adult nervous system is shown to alter levels or splicing of >970 mRNAs, most of which are distinct from the RNAs whose maturation is dependent on TDP-43. Nonetheless, only 55 RNAs are reduced upon depletion of either TDP-43 or FUS/TLS from mouse brain and human neurons differentiated from pluripotent stem cells, including mRNAs transcribed from genes with exceptionally long introns and that encode proteins essential for neuronal integrity. A subset of these is significantly lowered in FUS/TLSR521G and TDP-43G298S mutant fibroblasts and in TDP-43 aggregate-containing motor neurons in sporadic ALS, evidence pointing to a common loss-of-function pathway as one component underlying motor neuron death from misregulation of TDP-43 or FUS/TLS. CLIP of Fus/Tls in 8 week mouse brain and adult human brain
Project description:FUS/TLS and TDP-43 are RNA/DNA-binding proteins integrally involved in amyotrophic lateral sclerosis (ALS) and frontal temporal dementia. FUS/TLS is shown to bind RNAs from >5,500 genes in mouse and human brain, primarily through a GUGGU binding motif. A characteristic sawtooth-like binding pattern is identified, supporting co-transcriptional deposition of FUS/TLS. Depletion of FUS/TLS from the adult nervous system is shown to alter levels or splicing of >970 mRNAs, most of which are distinct from the RNAs whose maturation is dependent on TDP-43. Nonetheless, only 55 RNAs are reduced upon depletion of either TDP-43 or FUS/TLS from mouse brain and human neurons differentiated from pluripotent stem cells, including mRNAs transcribed from genes with exceptionally long introns and that encode proteins essential for neuronal integrity. A subset of these is significantly lowered in FUS/TLSR521G and TDP-43G298S mutant fibroblasts and in TDP-43 aggregate-containing motor neurons in sporadic ALS, evidence pointing to a common loss-of-function pathway as one component underlying motor neuron death from misregulation of TDP-43 or FUS/TLS. RNA-Seq of Fus/Tls in 8 week mouse brain
Project description:FUS/TLS and TDP-43 are RNA/DNA-binding proteins integrally involved in amyotrophic lateral sclerosis (ALS) and frontal temporal dementia. FUS/TLS is shown to bind RNAs from >5,500 genes in mouse and human brain, primarily through a GUGGU binding motif. A characteristic sawtooth-like binding pattern is identified, supporting co-transcriptional deposition of FUS/TLS. Depletion of FUS/TLS from the adult nervous system is shown to alter levels or splicing of >970 mRNAs, most of which are distinct from the RNAs whose maturation is dependent on TDP-43. Nonetheless, only 55 RNAs are reduced upon depletion of either TDP-43 or FUS/TLS from mouse brain and human neurons differentiated from pluripotent stem cells, including mRNAs transcribed from genes with exceptionally long introns and that encode proteins essential for neuronal integrity. A subset of these is significantly lowered in FUS/TLSR521G and TDP-43G298S mutant fibroblasts and in TDP-43 aggregate-containing motor neurons in sporadic ALS, evidence pointing to a common loss-of-function pathway as one component underlying motor neuron death from misregulation of TDP-43 or FUS/TLS.