The role of the U12-dependent spliceosome in differentiation

Maureen Veronica Akinyi, Mariia Shcherbii, Mikko Juhani Frilander

Research output: Conference materialsAbstractResearch

Abstract

Previous studies in our laboratory have identified an auto/crossregulation system that regulates minor spliceosome cellular abundance via core 48K and 65K proteins [1]. This regulatory program uses evolutionarily ultraconserved sequence elements (USSE) located in the introns of both 65K and 48K pre-mRNAs that function as splicing enhancers. The USSE element employs alternative splicing activated by U11 snRNP binding, to generate non-functional mRNA isoforms that are either degraded by nonsense-mediated decay (NMD) in the case of 48K following the inclusion of a mini exon, or trapped in the nucleus in the case of 65K, due to a long 3’UTR [1]. More recently, work in our laboratory has shown that the USSE-mediated downregulation of 65K is strongly activated during neuronal differentiation which suggested that the minor spliceosome may play a role in cellular differentiation and proliferation programs [2]. To address the significance of 65K USSE mediated regulation during differentiation we examined three different differentiation models. For neuronal differentiation, we used the SH-SY5Y neuronal differentiation model, which can be induced to differentiate into dopaminergic-like neurons by retinoic acid. We also analyzed 65K downregulation in differentiating pancreatic and bi-potential gonad cells.
During normal neuronal differentiation, 65K protein expression is downregulated due to a USSE-dependent shift toward the long 3’UTR isoform. We asked if this isoform shift is essential for neuronal differentiation in SH-SY5Y cells by blocking the USSE element using an antisense morpholino oligonucleotide, which results in a shift towards production of functional short 3´UTR containing isoform. We found that the differentiation is indeed disturbed as the neurite outgrowth appeared to be inhibited and there was enrichment of fibroblast-like cells as opposed to mature neurons. Blocking the 65K-USSE in later stages of the differentiation pathway led to a rapid degeneration of already established synaptic connections. With regards to other differentiation systems, our preliminary experiments reveal that 65K-USSE mediated downregulation is also operational in pancreas and bi-potential gonad cell differentiation, however the significance of this regulation for the differentiation process is yet to be established. Thus far, our preliminary data strongly suggest that 65K USSE–mediated regulation, and consequently the control of minor spliceosome abundance, appears to be important for neuronal survival and development. This may have implications in minor spliceosome-associated diseases that are reported to have neuronal defects such as Lowry Wood Syndrome (LWS), microcephalic osteodysplastic primordial dwarfism, type 1 (MOPD1) or Taybi-Linder syndrome (TALS), Roifman syndrome, and Early Onset Cerebellar Ataxia (EOCA) [3,4]. This work may provide a significant leap forward in understanding the regulatory function and targets of the minor spliceosome and will help to understand the human diseases resulting from the minor spliceosome dysfunction.

1. Niemelä (2015) RNA Biol. 12:1256–1264.
2. Verbeeren (2017). PLoS Genetics, 13(5):e1006824.
3. Verma (2018) Semin. Cell Dev. Biol., 79, 103-112.
4. Jutzi (2018) Cell Stress, 2:40-54
Original languageEnglish
Publication statusPublished - 18 Nov 2018
MoE publication typeNot Eligible
EventRNA and Disease 2018 - Uppsala, Sweden
Duration: 18 Nov 201820 Nov 2018
https://rnadiseases2018.com/

Conference

ConferenceRNA and Disease 2018
CountrySweden
CityUppsala
Period18/11/201820/11/2018
Internet address

Fields of Science

  • 1182 Biochemistry, cell and molecular biology
  • RNA Biology, RNA Splicing, Minor Spliceosome

Cite this

Akinyi, M. V., Shcherbii, M., & Frilander, M. J. (2018). The role of the U12-dependent spliceosome in differentiation. Abstract from RNA and Disease 2018, Uppsala, Sweden.
Akinyi, Maureen Veronica ; Shcherbii, Mariia ; Frilander, Mikko Juhani. / The role of the U12-dependent spliceosome in differentiation. Abstract from RNA and Disease 2018, Uppsala, Sweden.
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Akinyi, MV, Shcherbii, M & Frilander, MJ 2018, 'The role of the U12-dependent spliceosome in differentiation' RNA and Disease 2018, Uppsala, Sweden, 18/11/2018 - 20/11/2018, .

The role of the U12-dependent spliceosome in differentiation. / Akinyi, Maureen Veronica; Shcherbii, Mariia; Frilander, Mikko Juhani.

2018. Abstract from RNA and Disease 2018, Uppsala, Sweden.

Research output: Conference materialsAbstractResearch

TY - CONF

T1 - The role of the U12-dependent spliceosome in differentiation

AU - Akinyi, Maureen Veronica

AU - Shcherbii, Mariia

AU - Frilander, Mikko Juhani

PY - 2018/11/18

Y1 - 2018/11/18

N2 - Previous studies in our laboratory have identified an auto/crossregulation system that regulates minor spliceosome cellular abundance via core 48K and 65K proteins [1]. This regulatory program uses evolutionarily ultraconserved sequence elements (USSE) located in the introns of both 65K and 48K pre-mRNAs that function as splicing enhancers. The USSE element employs alternative splicing activated by U11 snRNP binding, to generate non-functional mRNA isoforms that are either degraded by nonsense-mediated decay (NMD) in the case of 48K following the inclusion of a mini exon, or trapped in the nucleus in the case of 65K, due to a long 3’UTR [1]. More recently, work in our laboratory has shown that the USSE-mediated downregulation of 65K is strongly activated during neuronal differentiation which suggested that the minor spliceosome may play a role in cellular differentiation and proliferation programs [2]. To address the significance of 65K USSE mediated regulation during differentiation we examined three different differentiation models. For neuronal differentiation, we used the SH-SY5Y neuronal differentiation model, which can be induced to differentiate into dopaminergic-like neurons by retinoic acid. We also analyzed 65K downregulation in differentiating pancreatic and bi-potential gonad cells. During normal neuronal differentiation, 65K protein expression is downregulated due to a USSE-dependent shift toward the long 3’UTR isoform. We asked if this isoform shift is essential for neuronal differentiation in SH-SY5Y cells by blocking the USSE element using an antisense morpholino oligonucleotide, which results in a shift towards production of functional short 3´UTR containing isoform. We found that the differentiation is indeed disturbed as the neurite outgrowth appeared to be inhibited and there was enrichment of fibroblast-like cells as opposed to mature neurons. Blocking the 65K-USSE in later stages of the differentiation pathway led to a rapid degeneration of already established synaptic connections. With regards to other differentiation systems, our preliminary experiments reveal that 65K-USSE mediated downregulation is also operational in pancreas and bi-potential gonad cell differentiation, however the significance of this regulation for the differentiation process is yet to be established. Thus far, our preliminary data strongly suggest that 65K USSE–mediated regulation, and consequently the control of minor spliceosome abundance, appears to be important for neuronal survival and development. This may have implications in minor spliceosome-associated diseases that are reported to have neuronal defects such as Lowry Wood Syndrome (LWS), microcephalic osteodysplastic primordial dwarfism, type 1 (MOPD1) or Taybi-Linder syndrome (TALS), Roifman syndrome, and Early Onset Cerebellar Ataxia (EOCA) [3,4]. This work may provide a significant leap forward in understanding the regulatory function and targets of the minor spliceosome and will help to understand the human diseases resulting from the minor spliceosome dysfunction.1. Niemelä (2015) RNA Biol. 12:1256–1264.2. Verbeeren (2017). PLoS Genetics, 13(5):e1006824.3. Verma (2018) Semin. Cell Dev. Biol., 79, 103-112.4. Jutzi (2018) Cell Stress, 2:40-54

AB - Previous studies in our laboratory have identified an auto/crossregulation system that regulates minor spliceosome cellular abundance via core 48K and 65K proteins [1]. This regulatory program uses evolutionarily ultraconserved sequence elements (USSE) located in the introns of both 65K and 48K pre-mRNAs that function as splicing enhancers. The USSE element employs alternative splicing activated by U11 snRNP binding, to generate non-functional mRNA isoforms that are either degraded by nonsense-mediated decay (NMD) in the case of 48K following the inclusion of a mini exon, or trapped in the nucleus in the case of 65K, due to a long 3’UTR [1]. More recently, work in our laboratory has shown that the USSE-mediated downregulation of 65K is strongly activated during neuronal differentiation which suggested that the minor spliceosome may play a role in cellular differentiation and proliferation programs [2]. To address the significance of 65K USSE mediated regulation during differentiation we examined three different differentiation models. For neuronal differentiation, we used the SH-SY5Y neuronal differentiation model, which can be induced to differentiate into dopaminergic-like neurons by retinoic acid. We also analyzed 65K downregulation in differentiating pancreatic and bi-potential gonad cells. During normal neuronal differentiation, 65K protein expression is downregulated due to a USSE-dependent shift toward the long 3’UTR isoform. We asked if this isoform shift is essential for neuronal differentiation in SH-SY5Y cells by blocking the USSE element using an antisense morpholino oligonucleotide, which results in a shift towards production of functional short 3´UTR containing isoform. We found that the differentiation is indeed disturbed as the neurite outgrowth appeared to be inhibited and there was enrichment of fibroblast-like cells as opposed to mature neurons. Blocking the 65K-USSE in later stages of the differentiation pathway led to a rapid degeneration of already established synaptic connections. With regards to other differentiation systems, our preliminary experiments reveal that 65K-USSE mediated downregulation is also operational in pancreas and bi-potential gonad cell differentiation, however the significance of this regulation for the differentiation process is yet to be established. Thus far, our preliminary data strongly suggest that 65K USSE–mediated regulation, and consequently the control of minor spliceosome abundance, appears to be important for neuronal survival and development. This may have implications in minor spliceosome-associated diseases that are reported to have neuronal defects such as Lowry Wood Syndrome (LWS), microcephalic osteodysplastic primordial dwarfism, type 1 (MOPD1) or Taybi-Linder syndrome (TALS), Roifman syndrome, and Early Onset Cerebellar Ataxia (EOCA) [3,4]. This work may provide a significant leap forward in understanding the regulatory function and targets of the minor spliceosome and will help to understand the human diseases resulting from the minor spliceosome dysfunction.1. Niemelä (2015) RNA Biol. 12:1256–1264.2. Verbeeren (2017). PLoS Genetics, 13(5):e1006824.3. Verma (2018) Semin. Cell Dev. Biol., 79, 103-112.4. Jutzi (2018) Cell Stress, 2:40-54

KW - 1182 Biochemistry, cell and molecular biology

KW - RNA Biology, RNA Splicing, Minor Spliceosome

M3 - Abstract

ER -

Akinyi MV, Shcherbii M, Frilander MJ. The role of the U12-dependent spliceosome in differentiation. 2018. Abstract from RNA and Disease 2018, Uppsala, Sweden.