Rocchi, A. | bioRxiv Science

bioRxiv2025

REST/NRSF phosphorylation by CaMKIV regulates its transcriptional repressor activity and half-life

REST is a repressor of a large cluster of neural genes that homeostatically regulates neural activity. However, whether REST can be regulated by Ca2+ and Ca2+-activated kinases is unknown. We investigated Ca2+/calmodulin-dependent protein kinases (CaMKs) as upstream regulators of REST fate and activity. We show that REST is phosphorylated by CaMKIV at Ser-322 site located within the linker between the 5th-6th Zn-finger domains. Phosphomimic REST mutant in Serine-322 decreased REST repressor activity and caused its transition from nucleus to cytosol, followed by degradation. Molecular dynamics simulations of the phosphomimic N-terminal REST and the DNA RE1 sequence revealed a sharp decrease in the stability of the REST-RE1 binding interface. Moreover, the homeostatic effects of CaMKIV on the amplitude of excitatory synaptic currents were inhibited by the genetic deletion of REST. The results demonstrate that CaMKIV phosphorylation has a crucial role in the homeostatic regulation of REST levels and repressor activity. TeaserCaMKIV phosphorylation homeostatically regulates the repressor activity of REST on neural genes and its half-life.

neuroscience↗

bioRxiv2025

The inner dynamics of positive human-animal interactions: investigating the roles of oxytocin, opioids, dopamine, serotonin and the proteome

Research on the neuroendocrine basis of positive interactions has predominantly focused on oxytocin (OT), although dopamine (DA) and opioids also play crucial roles. Furthermore, these neurotransmitters are known to interact with each other but have seldom been studied concurrently. In this study, we quantified longitudinal changes in these neurotransmitters using a within-subject, 2 x 2 factorial design by varying human familiarity (familiar versus unfamiliar) and contact type (positive contacts versus ignoring) for 10 min human-pig interaction sessions. We repeatedly sampled cerebrospinal fluid from 10 pigs through a spinal catheter 65 and 5 min before the test and at 10, 30, 60, 120 and 240 min after the start of the test. Samples at various timepoints were analysed for OT, DA metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA), {beta}-endorphin opioids concentrations, and using proteomics to explore novel protein candidates. The test condition (human familiarity x contact type) had a significant effect on the concentration of {beta}-endorphin (F1,118.59 = 4.45; P = 0.04) and 5-HIAA (F1,73.47 = 5.02; P = 0.03), and tended to affect the concentration of oxytocin (F1, 119.8 = 3.19; P = 0.08) and DOPAC (F1,70.57 = 3.31; P = 0.07), but pair-wise comparisons were not significant. There was only a minor effect on the pigs behaviour, which suggests that the test conditions may have had limited effect. Nevertheless, this approach provides a valuable method to study neurotransmitter changes over time and simultaneously. Highlights- Oxytocin was higher when pigs were ignored than when they had positive contacts - Oxytocin was highest in the novel condition of an unfamiliar human ignoring the pig - Human familiarity and contact type affected {beta}-endorphin and 5-HIAA concentrations - Dopamine metabolites and the proteome were not affected by the test conditions

animal behavior and cognition↗