SUMOylation of FOXP1 regulates transcriptional repression via CtBP1 to drive dendritic morphogenesis

• Published in: Scientific reports Vol. 7; no. 1; pp. 877 - 12
• Main Authors: Rocca, Daniel L., Wilkinson, Kevin A., Henley, Jeremy M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.04.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 13; 13/1; 13/89; 13/95; 14/19; 631/378/340; 631/45/882; 82; 96; Animals; Calcium channels; Calcium channels (L-type); Calcium Channels, L-Type - genetics; Carrier Proteins - metabolism; Chromatin; Cognitive ability; Dendrites - metabolism; Down-Regulation; Forkhead protein; Forkhead Transcription Factors - chemistry; Forkhead Transcription Factors - genetics; Forkhead Transcription Factors - metabolism; Foxp1 protein; Gene silencing; Glutamate receptors; HEK293 Cells; Humanities and Social Sciences; Humans; Lysine; Lysine - chemistry; Morphogenesis; multidisciplinary; Mutation; N-Methyl-D-aspartic acid receptors; Neurons - metabolism; Rats; Receptors, N-Methyl-D-Aspartate - genetics; Repressor Proteins - chemistry; Repressor Proteins - genetics; Repressor Proteins - metabolism; Repressors; Science; Science (multidisciplinary); SUMO protein; Sumoylation; Transcription factors; Transcription Factors - metabolism; Transcription, Genetic
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-00707-6

Forkhead Box P (FOXP) transcriptional repressors play a major role in brain development and their dysfunction leads to human cognitive disorders. However, little is known about how the activity of these proteins is regulated. Here, we show that FOXP1 SUMOylation at lysine 670 is required for recruiting the co-repressor CtBP1 and transcriptional repression. FOXP1 SUMOylation is tightly controlled by neuronal activity, in which synapse to nucleus signalling, mediated via NMDAR and L-type calcium channels, results in rapid FOXP1 deSUMOylation. Knockdown of FOXP1 in cultured cortical neurons stunts dendritic outgrowth and this phenotype cannot be rescued by replacement with a non-SUMOylatable FOXP1-K670R mutant, indicating that SUMOylation of FOXP1 is essential for regulation of proper neuronal morphogenesis. These results suggest that activity-dependent SUMOylation of FOXP1 may be an important mediator of early cortical development and neuronal network formation in the brain.