The phosphorylation of synaptophysin, a major integral membrane protein of small synaptic vesicles, was found to be regulated in a Ca(2+)-dependent manner in rat cerebrocortical slices, synaptosome preparations, and highly purified synaptic vesicles isolated from rat forebrain. K(+)-induced depolarization of slices and synaptosomes prelabeled with 32P-orthophosphate produced a rapid, transient increase in serine phosphorylation of synaptophysin. In synaptosomes, the depolarization-dependent increase in synaptophysin phosphorylation required the presence of external Ca2+ in the incubation medium. The addition of Ca2+ plus calmodulin to purified synaptic vesicles resulted in a 4-fold increase in serine phosphorylation of synaptophysin, and this phosphorylation was antagonized by a peptide inhibitor of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II(. Purified rat forebrain CaM kinase II phosphorylated both purified synaptophysin and endogenous, vesicle-associated synaptophysin, and the resulting 2-dimensional chymotryptic phosphopeptide maps were similar to those derived from synaptophysin phosphorylated in cerebrocortical slices. These data demonstrate that Ca(2+)-dependent phosphorylation of synaptophysin, mediated by CaM kinase II, occurs under physiological conditions.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/syn.890130207 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
FGF21 Exhibits Neuroprotective Effects by Promoting 5-HTR-FGFR1 Heteroreceptor Complexes and Triggering MEK-ERK Signaling Pathway.
Mol Neurobiol
January 2025
School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China.
Approaches of promoting a neural milieu permissive for plasticity and resilience against neuronal injury are important strategies for the treatment of a range of neurological disorders. Fibroblast growth factor 21 (FGF21) which is known for its role as a potent regulator of glucose and energy metabolism has also proved to be neuroprotective against various mental diseases. However, the underlying molecular mechanisms remain elusive.
View Article and Find Full Text PDFAdiponectin targets the AMPK/mTOR signaling pathway to alleviate cognitive impairment in epilepsy.
Mol Med Rep
March 2025
Key Laboratory of Neurology of Hebei Province, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei 050000, P.R. China.
Among patients with chronic epilepsy, 70‑80% have cognitive impairment. To investigate the relationship between adiponectin (ADPN) and the cognitive level in epilepsy and its mechanism, 20 epileptic patients and 20 healthy controls were included for the assessment of the cognitive level. An ELISA was used to evaluate the serum ADPN level.
View Article and Find Full Text PDFXiaoxuming decoction enhanced neuroprotection after cerebral ischemia/reperfusion via the JAK2/STAT3 signaling pathway based on UPLC/HRMS, network pharmacology and experimental validation.
J Ethnopharmacol
January 2025
Encephalopathy Hospital, The First Affiliated Hospital of Henan University of Chinese Medicine, Henan, 450000, China. Electronic address:
Ethnopharmacological Relevance: Xiao-xu-ming decoction (XXMD), a prominent traditional Chinese medicinal formula historically revered for stroke treatment, demonstrates pronounced efficacy in ameliorating ischemic stroke injury.
Aim Of The Study: This study aims to investigate the effects and mechanisms of XXMD on neuroprotection subsequent to cerebral ischemia/reperfusion in vivo and in vitro.
Materials And Methods: Neurobehavioral test, TTC staining, HE staining and nissl staining were used to examine the neuroprotective effect of XXMD on cerebral ischemia-reperfusion injury induced by middle cerebral artery occlusion (MCAO) in rats.
Structural and functional alterations of neurons derived from sporadic Alzheimer's disease hiPSCs are associated with downregulation of the LIMK1-cofilin axis.
Alzheimers Res Ther
December 2024
Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168, Rome, Italy.
Background: Alzheimer's Disease (AD) is a neurodegenerative disorder characterized by the accumulation of pathological proteins and synaptic dysfunction. This study aims to investigate the molecular and functional differences between human induced pluripotent stem cells (hiPSCs) derived from patients with sporadic AD (sAD) and age-matched controls (healthy subjects, HS), focusing on their neuronal differentiation and synaptic properties in order to better understand the cellular and molecular mechanisms underlying AD pathology.
Methods: Skin fibroblasts from sAD patients (n = 5) and HS subjects (n = 5) were reprogrammed into hiPSCs using non-integrating Sendai virus vectors.
Anxio-depressive phenotype and impaired memory in mice with a conditional knockout of brain-derived neurotrophic factor in endothelial cells.
Am J Physiol Cell Physiol
January 2025
EFS, INSERM, UMR 1098 RIGHT, Université de Franche-Comté, Besançon, France.
The present study investigated the role of endothelial brain-derived neurotrophic factor (BDNF) in cognition. Male adult mice with a selective knockout of BDNF in endothelial cells () and their wild-type (WT) littermates were subjected to tests for detection of anxiety- and depression-like behaviors and impaired recognition memory. Neuronal activity and synaptogenesis were assessed from hippocampal levels of c-fos and synaptophysin, respectively, and cerebral capillary density from forebrain levels of CD31.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!