Synaptic Vesicle and Synaptic Membrane Glycoproteins during Pre- and Postnatal Development of Mouse Cerebral Cortex, Cerebellum and Spinal Cord

Abstract

Glycoproteins of synaptic vesicles and synaptic membranes play an important role during the process of synaptogenesis. In order to study the temporal expression of specific carbohydrates and the expression of selected neural proteins, we used peroxidase-conjugated lectin overlays on Western blots and immunoblots of synaptic vesicles and synaptic membranes isolated from pre- and postnatal mouse cerebral cortex, cerebellum and spinal cord. Our lectin overlays on Western blots showed that (1) the synaptic vesicle glycoproteins, gp80–100, gp47 and gp44, and (2) the synaptic membrane glycoproteins, gp180, gp72, gp70 and gp34, show temporal regulation of expression of carbohydrate moieties. Quite significantly, gp47 showed a decrease in the vesicles coinciding with an increase in membranes suggesting a shift in localization. Anti neural cell adhesion molecule (N-CAM) antibody cross-reacted with gp180. The developmental expression of synaptotagmin 1, a well characterized glycoprotein of synaptic vesicle, was determined by immunoblots analysis. Anti synaptosomal-associated protein 25 (SNAP-25) antibody immunoblots were performed in order to compare our results with a developmentally regulated synaptosomal protein demonstrating expression coincident with synaptogenesis. Our immunoblot studies showed that (1) N-CAM (gp180) immunoreactivity decrease with development; (2) the expression of synaptotagmin 1 and SNAP-25 increases as development progresses, and (3) synaptotagmin 1 and SNAP-25 show a shift in subcellular localization (from synaptic vesicle to synaptic membrane) during development, thereby indicating that these proteins are first identified in a vesicular fraction. Thus, our data suggest that synaptic vesicle and synaptic membrane glycoproteins show temporal regulation of specific carbohydrates as well as protein expression during development, which may be a key factor to our understanding of the process of synaptogenesis.

Maturation of Ribbon Synapses in Hair Cells Is Driven by Thyroid Hormone

“…This adds to previous work describing a developmental upregulation of cysteine string protein in IHCs (Eybalin et al, 2002), which serves as a presynaptic cochaperone (Schmitz et al, 2006). The TH-dependent increase of mRNA abundance for the two SNAREs in the cerebellum is in line with previous reports of a developmental SNAP25 protein upregulation accompanying synaptogenesis (Mayanil and Knepper, 1993;Bark et al, 1995) and a TH dependence of cerebellar development (Vincent et al, 1982;Mayanil and Knepper, 1993;Hashimoto et al, 2001;Bernal, 2005).…”

Developmental changes of synaptic proteins expression within the hippocampal formation of the rat

“…The amount of immunopositive terminals decreased gradually, and only a few labeled fibers were found. A shift of SNAP-25 and SYN from cell bodies and fibrous to punctate immunoreactivity shows that the process of maturation of synaptic terminals has been finished (Oyler et al 1991);Catsicas et al 1991;Osen-Sand et al 1993;Mayanil and Knepper 1993;Osen-Sand et al 1996;Marti et al 1998). …”

Regulated Vesicular Trafficking of Specific PCDH15 and VLGR1 Variants in Auditory Hair Cells

“…SNAP25 is a peripheral plasma membrane associated protein that interacts with synaptobrevin and syntaxin I to form the soluble NSF ( N -ethylmaleimide-sensitive fusion protein) attachment protein receptor (SNARE) complex involved in synaptic vesicle docking at the site of neurotransmitter release (Oyler et al, 1989; Söllner et al, 1993; Safieddine and Wenthold, 1999; Wenthold et al, 2002). However, during brain and cochlea maturation, a role in synaptic development has been suggested for SNAP25 where SNAP25a is found primarily in vesicles (Mayanil and Knepper, 1993; Bark et al, 1995). Co-localization of SNAP25 and CDH23 has been demonstrated at the base of cochlear and vestibular hair cells and neuronal fibers (Lagziel et al, 2009).…”

“…Figure 14 (top panels) demonstrates that there is indeed an association between SNAP25 and some of the VLGR1 synaptic variants (Zallocchi et al, 2012). We used both P1 inner ear and also P3 brain since SNAP25 and VLGR1 are highly co-expressed in the same cortical areas during brain development (Mayanil and Knepper, 1993; Bark et al, 1995; Yagi et al, 2005). The fact that we observed different variants immunoprecipitated from the inner ear ( Vlgr1f/g/o and Vlgr1l ) versus brain ( Vlgr1m ) suggests that the interactions between SNAP25 and the VLGR1 EAR variants are tissue specific (and likely developmentally regulated).…”