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Characterization of the transcripts and protein isoforms for cytoplasmic polyadenylation element binding protein-3 (CPEB3) in the mouse retina.

Wang XP, Cooper NG - BMC Mol. Biol. (2009)

Bottom Line: The relative abundance of the patterns in the retina is demonstrated.The level of CPEB3 was up-regulated in the retina during development.The presence of multiple CPEB3 isoforms indicates remarkable complexity in the regulation and function of CPEB3.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anatomical Sciences and Neurobiology, Health Sciences Campus, 500 S, Preston Street, University of Louisville, Louisville, KY, USA. x0wang04@gwise.louisville.edu

ABSTRACT

Background: Cytoplasmic polyadenylation element binding proteins (CPEBs) regulate translation by binding to regulatory motifs of defined mRNA targets. This translational mechanism has been shown to play a critical role in oocyte maturation, early development, and memory formation in the hippocampus. Little is known about the presence or functions of CPEBs in the retina. The purpose of the current study is to investigate the alternative splicing isoforms of a particular CPEB, CPEB3, based on current databases, and to characterize the expression of CPEB3 in the retina.

Results: In this study, we have characterized CPEB3, whose putative role is to regulate the translation of GluR2 mRNA. We identify the presence of multiple alternative splicing isoforms of CPEB3 transcripts and proteins in the current databases. We report the presence of eight alternative splicing patterns of CPEB3, including a novel one, in the mouse retina. All but one of the patterns appear to be ubiquitous in 13 types of tissue examined. The relative abundance of the patterns in the retina is demonstrated. Experimentally, we show that CPEB3 expression is increased in a time-dependent manner during the course of postnatal development, and CPEB3 is localized mostly in the inner retina, including retinal ganglion cells.

Conclusion: The level of CPEB3 was up-regulated in the retina during development. The presence of multiple CPEB3 isoforms indicates remarkable complexity in the regulation and function of CPEB3.

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Related in: MedlinePlus

The presence of CPEB3 in P60 mouse retina. We used double-immunofluorescence labeling with antibodies to CPEB3 and ChAT. ChAT is a marker for cholinergic amacrine cells. A few cells in the RGC layer were double-labeled with ChAT and CPEB3 antibodies, as indicated with the arrows. This suggested that a few CPEB3 positive cells in the RGC layer were displaced amacrine cells. The size of such cells was usually smaller than those cells staining positive for both CPEB3 and Map1a. The INL was also labeled with CPEB3, with the innermost cells more intensely labeled. A few cells in the INL appeared to be double-immunopositive for ChAT and CPEB3 (arrowhead), suggesting that some CPEB3 positive cells in the INL were cholinergic amacrine cells. Both the IPL and the OPL were labeled with CPEB3. Scale bar represented 50 μm.
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Figure 9: The presence of CPEB3 in P60 mouse retina. We used double-immunofluorescence labeling with antibodies to CPEB3 and ChAT. ChAT is a marker for cholinergic amacrine cells. A few cells in the RGC layer were double-labeled with ChAT and CPEB3 antibodies, as indicated with the arrows. This suggested that a few CPEB3 positive cells in the RGC layer were displaced amacrine cells. The size of such cells was usually smaller than those cells staining positive for both CPEB3 and Map1a. The INL was also labeled with CPEB3, with the innermost cells more intensely labeled. A few cells in the INL appeared to be double-immunopositive for ChAT and CPEB3 (arrowhead), suggesting that some CPEB3 positive cells in the INL were cholinergic amacrine cells. Both the IPL and the OPL were labeled with CPEB3. Scale bar represented 50 μm.

Mentions: To confirm the expression pattern of CPEB3 mRNA and to better define the cell types containing CPEB3 protein, fluorescence immunocytochemistry with an antibody to CPEB3 was used. A pattern was observed which was similar to that seen for the localization by in situ hybridization. CPEB3 protein was strongly expressed in cells located within the RGC layer, and to a less extent, within cells of the inner boundary of the INL (figure 8, 9). Both the inner plexiform layer (IPL) and the outer plexiform layer (OPL) also showed pronounced immunolabeling of CPEB3. To define the type of cells which express CPEB3 we used double immunolabeling with cell type-specific markers in combination with CPEB3. The ganglion cell-specific marker microtubule-associated protein 1a (Map1a) [34,35], and the cholinergic amacrine cell marker choline acetyl transferase (ChAT) [36-41], were used. Confocal microscope images indicated that most of the anti-CPEB3 labeled cells in the RGC layer were retinal ganglion cells (figure 8), and a few were displaced amacrine cells (figure 9).


Characterization of the transcripts and protein isoforms for cytoplasmic polyadenylation element binding protein-3 (CPEB3) in the mouse retina.

Wang XP, Cooper NG - BMC Mol. Biol. (2009)

The presence of CPEB3 in P60 mouse retina. We used double-immunofluorescence labeling with antibodies to CPEB3 and ChAT. ChAT is a marker for cholinergic amacrine cells. A few cells in the RGC layer were double-labeled with ChAT and CPEB3 antibodies, as indicated with the arrows. This suggested that a few CPEB3 positive cells in the RGC layer were displaced amacrine cells. The size of such cells was usually smaller than those cells staining positive for both CPEB3 and Map1a. The INL was also labeled with CPEB3, with the innermost cells more intensely labeled. A few cells in the INL appeared to be double-immunopositive for ChAT and CPEB3 (arrowhead), suggesting that some CPEB3 positive cells in the INL were cholinergic amacrine cells. Both the IPL and the OPL were labeled with CPEB3. Scale bar represented 50 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC2807433&req=5

Figure 9: The presence of CPEB3 in P60 mouse retina. We used double-immunofluorescence labeling with antibodies to CPEB3 and ChAT. ChAT is a marker for cholinergic amacrine cells. A few cells in the RGC layer were double-labeled with ChAT and CPEB3 antibodies, as indicated with the arrows. This suggested that a few CPEB3 positive cells in the RGC layer were displaced amacrine cells. The size of such cells was usually smaller than those cells staining positive for both CPEB3 and Map1a. The INL was also labeled with CPEB3, with the innermost cells more intensely labeled. A few cells in the INL appeared to be double-immunopositive for ChAT and CPEB3 (arrowhead), suggesting that some CPEB3 positive cells in the INL were cholinergic amacrine cells. Both the IPL and the OPL were labeled with CPEB3. Scale bar represented 50 μm.
Mentions: To confirm the expression pattern of CPEB3 mRNA and to better define the cell types containing CPEB3 protein, fluorescence immunocytochemistry with an antibody to CPEB3 was used. A pattern was observed which was similar to that seen for the localization by in situ hybridization. CPEB3 protein was strongly expressed in cells located within the RGC layer, and to a less extent, within cells of the inner boundary of the INL (figure 8, 9). Both the inner plexiform layer (IPL) and the outer plexiform layer (OPL) also showed pronounced immunolabeling of CPEB3. To define the type of cells which express CPEB3 we used double immunolabeling with cell type-specific markers in combination with CPEB3. The ganglion cell-specific marker microtubule-associated protein 1a (Map1a) [34,35], and the cholinergic amacrine cell marker choline acetyl transferase (ChAT) [36-41], were used. Confocal microscope images indicated that most of the anti-CPEB3 labeled cells in the RGC layer were retinal ganglion cells (figure 8), and a few were displaced amacrine cells (figure 9).

Bottom Line: The relative abundance of the patterns in the retina is demonstrated.The level of CPEB3 was up-regulated in the retina during development.The presence of multiple CPEB3 isoforms indicates remarkable complexity in the regulation and function of CPEB3.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Anatomical Sciences and Neurobiology, Health Sciences Campus, 500 S, Preston Street, University of Louisville, Louisville, KY, USA. x0wang04@gwise.louisville.edu

ABSTRACT

Background: Cytoplasmic polyadenylation element binding proteins (CPEBs) regulate translation by binding to regulatory motifs of defined mRNA targets. This translational mechanism has been shown to play a critical role in oocyte maturation, early development, and memory formation in the hippocampus. Little is known about the presence or functions of CPEBs in the retina. The purpose of the current study is to investigate the alternative splicing isoforms of a particular CPEB, CPEB3, based on current databases, and to characterize the expression of CPEB3 in the retina.

Results: In this study, we have characterized CPEB3, whose putative role is to regulate the translation of GluR2 mRNA. We identify the presence of multiple alternative splicing isoforms of CPEB3 transcripts and proteins in the current databases. We report the presence of eight alternative splicing patterns of CPEB3, including a novel one, in the mouse retina. All but one of the patterns appear to be ubiquitous in 13 types of tissue examined. The relative abundance of the patterns in the retina is demonstrated. Experimentally, we show that CPEB3 expression is increased in a time-dependent manner during the course of postnatal development, and CPEB3 is localized mostly in the inner retina, including retinal ganglion cells.

Conclusion: The level of CPEB3 was up-regulated in the retina during development. The presence of multiple CPEB3 isoforms indicates remarkable complexity in the regulation and function of CPEB3.

Show MeSH
Related in: MedlinePlus