@article {53, title = {Differential NOVA2-Mediated Splicing in Excitatory and Inhibitory Neurons Regulates Cortical Development and Cerebellar Function.}, journal = {Neuron}, volume = {101}, year = {2019}, month = {2019 Feb 20}, pages = {707-720.e5}, abstract = {

RNA-binding proteins (RBPs) regulate genetic diversity, but the degree to which they do so in individual cell types in~vivo is unknown. We developed NOVA2 cTag-crosslinking and immunoprecipitation (CLIP) to generate functional RBP-RNA maps from different neuronal populations in the mouse brain. Combining cell type datasets from Nova2-cTag and Nova2 conditional knockout mice revealed differential NOVA2 regulatory actions on alternative splicing (AS) on the same transcripts expressed in different neurons. This includes functional differences in transcripts expressed in cortical and cerebellar excitatory versus inhibitory neurons, where we find NOVA2 is required for, respectively, development of laminar structure, motor coordination, and synapse formation. We also find that NOVA2-regulated AS is coupled to NOVA2 regulation of intron retention in hundreds of transcripts, which can sequester the trans-acting splicing factor PTBP2. In summary, cTag-CLIP complements single-cell RNA sequencing (RNA-seq) studies by providing a means for understanding RNA regulation of functional cell diversity.

}, issn = {1097-4199}, doi = {10.1016/j.neuron.2018.12.019}, author = {Saito, Yuhki and Yuan, Yuan and Zucker-Scharff, Ilana and Fak, John J and Jereb, Sa{\v s}a and Tajima, Yoko and Licatalosi, Donny D and Darnell, Robert B} } @article {47, title = {Cell type-specific CLIP reveals that NOVA regulates cytoskeleton interactions in motoneurons.}, journal = {Genome Biol}, volume = {19}, year = {2018}, month = {2018 08 15}, pages = {117}, abstract = {

BACKGROUND: Alternative RNA processing plays an essential role in shaping cell identity and connectivity in the central nervous system. This is believed to involve differential regulation of RNA processing in various cell types. However, in vivo study of cell type-specific post-transcriptional regulation has been a challenge. Here, we describe a sensitive and stringent method combining genetics and CLIP (crosslinking and immunoprecipitation) to globally identify regulatory interactions between NOVA and RNA in the mouse spinal cord motoneurons.

RESULTS: We developed a means of undertaking motoneuron-specific CLIP to explore motoneuron-specific protein-RNA interactions relative to studies of the whole spinal cord in mouse. This allowed us to pinpoint differential RNA regulation specific to motoneurons, revealing a major role for NOVA in regulating cytoskeleton interactions in motoneurons. In particular, NOVA specifically promotes the palmitoylated isoform of the cytoskeleton protein Septin 8 in motoneurons, which enhances dendritic arborization.

CONCLUSIONS: Our study demonstrates that cell type-specific RNA regulation is important for fine tuning motoneuron physiology and highlights the value of defining RNA processing regulation at single cell type resolution.

}, keywords = {Alternative Splicing, Amino Acid Sequence, Animals, Cercopithecus aethiops, Chromosomes, Artificial, Bacterial, COS Cells, Cross-Linking Reagents, Cytoskeleton, Dendrites, Exons, Immunoprecipitation, Lipoylation, Mice, Mice, Transgenic, Motor Neurons, Nerve Tissue Proteins, NIH 3T3 Cells, Pseudopodia, RNA, RNA-Binding Proteins, Septins, Transcriptome}, issn = {1474-760X}, doi = {10.1186/s13059-018-1493-2}, author = {Yuan, Yuan and Xie, Shirley and Darnell, Jennifer C and Darnell, Andrew J and Saito, Yuhki and Phatnani, Hemali and Murphy, Elisabeth A and Zhang, Chaolin and Maniatis, Tom and Darnell, Robert B} } @article {24, title = {cTag-PAPERCLIP Reveals Alternative Polyadenylation Promotes Cell-Type Specific Protein Diversity and Shifts Araf Isoforms with Microglia Activation.}, journal = {Neuron}, volume = {95}, year = {2017}, month = {2017 Sep 13}, pages = {1334-1349.e5}, abstract = {

Alternative polyadenylation (APA) is increasingly recognized to regulate gene expression across different cell types, but obtaining APA maps from individual cell types typically requires prior purification, a stressful procedure that can itself alter cellular states. Here, we describe a new platform, cTag-PAPERCLIP,~that generates APA profiles from single cell populations in intact tissues; cTag-PAPERCLIP requires no tissue dissociation and preserves transcripts in native states. Applying cTag-PAPERCLIP to profile four major cell types in the mouse brain revealed common APA preferences between excitatory and inhibitory neurons distinct from astrocytes~and microglia, regulated in part by neuron-specific~RNA-binding proteins NOVA2 and PTBP2. We further~identified a role of APA in switching Araf protein isoforms during microglia activation, impacting production of downstream inflammatory cytokines. Our results demonstrate the broad applicability of cTag-PAPERCLIP and a previously undiscovered role of APA in contributing to protein diversity between different cell types and cellular states within the brain.

}, keywords = {Animals, Antigens, Neoplasm, Astrocytes, Brain, Cells, Cultured, Female, Humans, Male, Mice, Microglia, Nerve Tissue Proteins, Neuro-Oncological Ventral Antigen, Neurons, Organ Specificity, Polyadenylation, Polypyrimidine Tract-Binding Protein, Protein Isoforms, Protein Serine-Threonine Kinases, RNA-Binding Proteins}, issn = {1097-4199}, doi = {10.1016/j.neuron.2017.08.024}, author = {Hwang, Hun-Way and Saito, Yuhki and Park, Christopher Y and Blach{\`e}re, Nathalie E and Tajima, Yoko and Fak, John J and Zucker-Scharff, Ilana and Darnell, Robert B} }