TDP-43 and NOVA-1 RNA-binding proteins as competitive splicing regulators of the schizophrenia-associated TNIK gene

Publication date: Available online 2 August 2019Source: Biochimica et Biophysica Acta (BBA) - Gene Regulatory MechanismsAuthor(s): Valentina Gumina, Claudia Colombrita, Claudia Fallini, Patrizia Bossolasco, Anna Maria Maraschi, John E. Landers, Vincenzo Silani, Antonia RattiAbstractThe RNA-binding protein TDP-43, associated to amyotrophic lateral sclerosis and frontotemporal dementia, regulates the alternative splicing of several genes, including the skipping of TNIK exon 15. TNIK, a genetic risk factor for schizophrenia and causative for intellectual disability, encodes for a Ser/Thr kinase regulating negatively F-actin dynamics.Here we show that in the human adult nervous system TNIK exon 15 is mostly included compared to the other tissues and that, during neuronal differentiation of human induced pluripotent stem cells and of human neuroblastoma cells, TNIK exon 15 inclusion increases independently of TDP-43 protein content. By studying the possible molecular interplay of TDP-43 with brain-specific splicing factors, we found that the neuronal NOVA-1 protein competitively inhibits both TDP-43 and hnRNPA2/B1 skipping activity on TNIK by means of a RNA-dependent interaction and that this competitive mechanism is common to other TDP-43 RNA targets. We also show that the TNIK protein isoforms including/excluding exon 15 differently regulate cell spreading in non-neuronal cells and neuritogenesis in primary cortical neurons.Our data suggest a complex regulation between the ubiqu...
Source: Biochimica et Biophysica Acta (BBA) Gene Regulatory Mechanisms - Category: Genetics & Stem Cells Source Type: research