S-Nitrosylation of CRTC1 in Alzheimer's disease impairs CREB-dependent gene expression induced by neuronal activity.

cAMP response element-binding protein (CREB)-regulated transcription coactivator 1 (CRTC1) plays an important role in synaptic plasticity, learning, and long-term memory formation through the regulation of neuronal activity-dependent gene expression, and CRTC1 dysregulation is implicated in Alzheimer's disease (AD). Here, we show that increased S-nitrosylation of CRTC1 (forming SNO-CRTC1), as seen in cell-based, animal-based, and human-induced pluripotent stem cell (hiPSC)-derived cerebrocortical neuron-based AD models, disrupts its binding with CREB and diminishes the activity-dependent gene expression mediated by the CRTC1/CREB pathway. We identified Cys216 of CRTC1 as the primary target of S-nitrosylation by nitric oxide (NO)-related species.

Redox regulation, protein S-nitrosylation, and synapse loss in Alzheimer's and related dementias.

Redox-mediated posttranslational modification, as exemplified by protein S-nitrosylation, modulates protein activity and function in both health and disease. Here, we review recent findings that show how normal aging, infection/inflammation, trauma, environmental toxins, and diseases associated with protein aggregation can each trigger excessive nitrosative stress, resulting in aberrant protein S-nitrosylation and hence dysfunctional protein networks. These redox reactions contribute to the etiology of multiple neurodegenerative disorders as well as systemic diseases.

Using in vivo intact structure for system-wide quantitative analysis of changes in proteins.

Mass spectrometry-based methods can provide a global expression profile and structural readout of proteins in complex systems. Preserving the in vivo conformation of proteins in their innate state is challenging during proteomic experiments. Here, we introduce a whole animal in vivo protein footprinting method using perfusion of reagents to add dimethyl labels to exposed lysine residues on intact proteins which provides information about protein conformation.

Dysregulation of miRNA expression and excitation in MEF2C autism patient hiPSC-neurons and cerebral organoids.

MEF2C is a critical transcription factor in neurodevelopment, whose loss-of-function mutation in humans results in MEF2C haploinsufficiency syndrome (MHS), a severe form of autism spectrum disorder (ASD)/intellectual disability (ID). Despite prior animal studies of MEF2C heterozygosity to mimic MHS, MHS-specific mutations have not been investigated previously, particularly in a human context as hiPSCs afford. Here, for the first time, we use patient hiPSC-derived cerebrocortical neurons and cerebral organoids to characterize MHS deficits.