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ZNF265--a novel spliceosomal protein able to induce alternative splicing.

Adams DJ, van der Weyden L, Mayeda A, Stamm S, Morris BJ, Rasko JE - J. Cell Biol. (2001)

Bottom Line: Transfection of HT-1080 cells with ZNF265-EGFP fusion constructs showed that nuclear localization of ZNF265 required the RS domain.Alignment with other RS domain-containing proteins revealed a high degree of SR dipeptide conservation.These data show that ZNF265 functions as a novel component of the mRNA processing machinery.

View Article: PubMed Central - PubMed

Affiliation: The University of Sydney, Basic & Clinical Genomics Laboratory, Department of Physiology and Institute for Biomedical Research, Sydney, NSW 2006, Australia.

ABSTRACT
The formation of the active spliceosome, its recruitment to active areas of transcription, and its role in pre-mRNA splicing depends on the association of a number of multifunctional serine/arginine-rich (SR) proteins. ZNF265 is an arginine/serine-rich (RS) domain containing zinc finger protein with conserved pre-mRNA splicing protein motifs. Here we show that ZNF265 immunoprecipitates from splicing extracts in association with mRNA, and that it is able to alter splicing patterns of Tra2-beta1 transcripts in a dose-dependent manner in HEK 293 cells. Yeast two-hybrid analysis and immunoprecipitation indicated interaction of ZNF265 with the essential splicing factor proteins U1-70K and U2AF(35). Confocal microscopy demonstrated colocalization of ZNF265 with the motor neuron gene product SMN, the snRNP protein U1-70K, the SR protein SC35, and with the transcriptosomal components p300 and YY1. Transfection of HT-1080 cells with ZNF265-EGFP fusion constructs showed that nuclear localization of ZNF265 required the RS domain. Alignment with other RS domain-containing proteins revealed a high degree of SR dipeptide conservation. These data show that ZNF265 functions as a novel component of the mRNA processing machinery.

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Subcellular colocalization of endogenous ZNF265 with endogenous nuclear factors. (A) Immunoblotting assay demonstrates specific recognition of ZNF265 by the polyclonal ZNF265 antibody (the arrow shows a 55-kD band), which was competed by ZNF265 oligopeptide antigen (2.5 μg/ml) in three replicate experiments. (B) Subcellular localization of various protein factors. Fixed Calu-6 cells were exposed to: (1st column) monoclonal antibodies against splicing factors U1-70K, Sm antigen, SC35, SMN, or transcriptosomal factors p300 and YY1, in respective rows, before incubation with Alexa 594 anti–mouse IgG (red); (2nd column) staining with anti-ZNF265 and detection with Alexa 488–conjugated anti–rabbit IgG (green); (3rd column) DAPI staining of nucleus (blue); (4th column) digital overlay of Z-series projections shown in columns 1 and 2 to demonstrate colocalization (yellow); (5th column) scattergrams of the overlayed projection shown in column 4. Each row represents the same field (width × height = 60 × 60 μm), acquired using three-channel confocal microscopy.
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fig1: Subcellular colocalization of endogenous ZNF265 with endogenous nuclear factors. (A) Immunoblotting assay demonstrates specific recognition of ZNF265 by the polyclonal ZNF265 antibody (the arrow shows a 55-kD band), which was competed by ZNF265 oligopeptide antigen (2.5 μg/ml) in three replicate experiments. (B) Subcellular localization of various protein factors. Fixed Calu-6 cells were exposed to: (1st column) monoclonal antibodies against splicing factors U1-70K, Sm antigen, SC35, SMN, or transcriptosomal factors p300 and YY1, in respective rows, before incubation with Alexa 594 anti–mouse IgG (red); (2nd column) staining with anti-ZNF265 and detection with Alexa 488–conjugated anti–rabbit IgG (green); (3rd column) DAPI staining of nucleus (blue); (4th column) digital overlay of Z-series projections shown in columns 1 and 2 to demonstrate colocalization (yellow); (5th column) scattergrams of the overlayed projection shown in column 4. Each row represents the same field (width × height = 60 × 60 μm), acquired using three-channel confocal microscopy.

Mentions: Using a polyclonal ZNF265 antibody (Fig. 1 A) and antibodies directed against specific components of the spliceosome, we observed nuclear colocalization of ZNF265 with the survival of motor neuron (SMN) protein, the authentic SR protein SC35 (at the periphery of the SC35-staining aggregates), and the snRNP protein U1-70K, but none with the common snRNP protein antigen Sm (Fig. 1 B). As expected, SMN showed some cytoplasmic localization (Pagliardini et al., 2000), but this did not overlap with the trace amount of cytoplasmic ZNF265 localization (Fig. 1 B). ZNF265 also colocalized with the transcription factors YY1 and p300 (Fig. 1 B), both of which have been shown to colocalize within active transcriptional compartments and, in the case of p300, with RNA polymerase II (Bannister and Kouzarides, 1996; Ogryzko et al., 1996; Yang et al., 1996; von Mikecz et al., 2000). These colocalizations are consistent with a role for ZNF265 in transcription and/or splicing. In this regard, ZNF265 may be cotranscriptionally recruited with RNA polymerase II to pre-mRNA transcripts, as has been reported for other RS domain–containing proteins (Corden and Patturajan, 1997).


ZNF265--a novel spliceosomal protein able to induce alternative splicing.

Adams DJ, van der Weyden L, Mayeda A, Stamm S, Morris BJ, Rasko JE - J. Cell Biol. (2001)

Subcellular colocalization of endogenous ZNF265 with endogenous nuclear factors. (A) Immunoblotting assay demonstrates specific recognition of ZNF265 by the polyclonal ZNF265 antibody (the arrow shows a 55-kD band), which was competed by ZNF265 oligopeptide antigen (2.5 μg/ml) in three replicate experiments. (B) Subcellular localization of various protein factors. Fixed Calu-6 cells were exposed to: (1st column) monoclonal antibodies against splicing factors U1-70K, Sm antigen, SC35, SMN, or transcriptosomal factors p300 and YY1, in respective rows, before incubation with Alexa 594 anti–mouse IgG (red); (2nd column) staining with anti-ZNF265 and detection with Alexa 488–conjugated anti–rabbit IgG (green); (3rd column) DAPI staining of nucleus (blue); (4th column) digital overlay of Z-series projections shown in columns 1 and 2 to demonstrate colocalization (yellow); (5th column) scattergrams of the overlayed projection shown in column 4. Each row represents the same field (width × height = 60 × 60 μm), acquired using three-channel confocal microscopy.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2196870&req=5

fig1: Subcellular colocalization of endogenous ZNF265 with endogenous nuclear factors. (A) Immunoblotting assay demonstrates specific recognition of ZNF265 by the polyclonal ZNF265 antibody (the arrow shows a 55-kD band), which was competed by ZNF265 oligopeptide antigen (2.5 μg/ml) in three replicate experiments. (B) Subcellular localization of various protein factors. Fixed Calu-6 cells were exposed to: (1st column) monoclonal antibodies against splicing factors U1-70K, Sm antigen, SC35, SMN, or transcriptosomal factors p300 and YY1, in respective rows, before incubation with Alexa 594 anti–mouse IgG (red); (2nd column) staining with anti-ZNF265 and detection with Alexa 488–conjugated anti–rabbit IgG (green); (3rd column) DAPI staining of nucleus (blue); (4th column) digital overlay of Z-series projections shown in columns 1 and 2 to demonstrate colocalization (yellow); (5th column) scattergrams of the overlayed projection shown in column 4. Each row represents the same field (width × height = 60 × 60 μm), acquired using three-channel confocal microscopy.
Mentions: Using a polyclonal ZNF265 antibody (Fig. 1 A) and antibodies directed against specific components of the spliceosome, we observed nuclear colocalization of ZNF265 with the survival of motor neuron (SMN) protein, the authentic SR protein SC35 (at the periphery of the SC35-staining aggregates), and the snRNP protein U1-70K, but none with the common snRNP protein antigen Sm (Fig. 1 B). As expected, SMN showed some cytoplasmic localization (Pagliardini et al., 2000), but this did not overlap with the trace amount of cytoplasmic ZNF265 localization (Fig. 1 B). ZNF265 also colocalized with the transcription factors YY1 and p300 (Fig. 1 B), both of which have been shown to colocalize within active transcriptional compartments and, in the case of p300, with RNA polymerase II (Bannister and Kouzarides, 1996; Ogryzko et al., 1996; Yang et al., 1996; von Mikecz et al., 2000). These colocalizations are consistent with a role for ZNF265 in transcription and/or splicing. In this regard, ZNF265 may be cotranscriptionally recruited with RNA polymerase II to pre-mRNA transcripts, as has been reported for other RS domain–containing proteins (Corden and Patturajan, 1997).

Bottom Line: Transfection of HT-1080 cells with ZNF265-EGFP fusion constructs showed that nuclear localization of ZNF265 required the RS domain.Alignment with other RS domain-containing proteins revealed a high degree of SR dipeptide conservation.These data show that ZNF265 functions as a novel component of the mRNA processing machinery.

View Article: PubMed Central - PubMed

Affiliation: The University of Sydney, Basic & Clinical Genomics Laboratory, Department of Physiology and Institute for Biomedical Research, Sydney, NSW 2006, Australia.

ABSTRACT
The formation of the active spliceosome, its recruitment to active areas of transcription, and its role in pre-mRNA splicing depends on the association of a number of multifunctional serine/arginine-rich (SR) proteins. ZNF265 is an arginine/serine-rich (RS) domain containing zinc finger protein with conserved pre-mRNA splicing protein motifs. Here we show that ZNF265 immunoprecipitates from splicing extracts in association with mRNA, and that it is able to alter splicing patterns of Tra2-beta1 transcripts in a dose-dependent manner in HEK 293 cells. Yeast two-hybrid analysis and immunoprecipitation indicated interaction of ZNF265 with the essential splicing factor proteins U1-70K and U2AF(35). Confocal microscopy demonstrated colocalization of ZNF265 with the motor neuron gene product SMN, the snRNP protein U1-70K, the SR protein SC35, and with the transcriptosomal components p300 and YY1. Transfection of HT-1080 cells with ZNF265-EGFP fusion constructs showed that nuclear localization of ZNF265 required the RS domain. Alignment with other RS domain-containing proteins revealed a high degree of SR dipeptide conservation. These data show that ZNF265 functions as a novel component of the mRNA processing machinery.

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