Annotated protein:Small ubiquitin-related modifier 2 (SUMO-2) (SMT3 homolog 2) (Ubiquitin-like protein SMT3B) (Smt3B). Gene symbol: SUMO2. Taxonomy: Mus musculus (Mouse). Uniprot ID: P61957
antibody wiki:
SynGO gene info:SynGO data @ SUMO2
Ontology domain:Cellular Component
SynGO term:postsynaptic cytosol (GO:0099524)
Synapse type(s):hippocampus, glutamatergic
Annotated paper:Colnaghi L, et al. "Super Resolution Microscopy of SUMO Proteins in Neurons" Front Cell Neurosci. 2019 Nov 1;13:486 PMID:31749687
Figure(s):Figure 1, 3, 4, S3, S4
Annotation description:"All SUMO proteins are expressed in an immature pro-form, in which they carry a C-terminal stretch of variable length (2-11 amino acids) after an invariant Gly-Gly motif that marks the C terminus of the mature protein. Removal of this C-terminal extension by SUMO-specific proteases is a prerequisite for the conjugation of SUMO to targets. The mature forms of SUMO2 and SUMO3 are 97% identical, but share only 50% sequence identity with SUMO1. SUMO1 and SUMO2/3 serve distinct functions, as they are conjugated to different target proteins in vivo." PMID:18000527
Thus antibodies tend to recognise both proteins and often SUMO2/3 is used to ambiguously refer to these proteins.

Figure 1, 3, 4, S3, S4: SIM super-resolution microscopy of hippocampal neurons showed various antibodies that all recognised SUMO2/3 were partially colocalized with synaptophysin (SYP) and PSD95 (DLG4).

It is likely that both SUMO2 and SUMO3 are omnipresent and this study detected both (and not only either) of these proteins with the "pan" antibodies. Further evidence for presence of both proteins at the synapse;
- SUMO2 was shown to conjugate to postsynaptic gephyrin/GPHN (PMID:27819299)
- SUMO2 knockout impaired the maintenance of hippocampal LTP (PMID:32910521)
- SUMO2 was shown to localize to PSD fractions (PMID:14532281)
- SUMO3 was shown to conjugate presynaptic protein mGluR7/GRM7 (PMID:26631532)
- SUMO1&3 were shown to conjugate to α-Synuclein (PMID:25607946)
- SUMO1&2&3 were shown to conjugate to CASK (PMID:18606847)
- SUMO1&2&3 were all detected in mass-spec of cortical synaptosomes with a unique peptide (PMID:32439598)

Authors reiterate that most SUMO2/3 is non-synaptic;
"We imaged endogenous SUMO2/3 using a custom-made antibody against the protein (Matsuzaki et al., 2015) along with two neuronal markers, NeuN and Map2. Similarly to what has been found in other types of cells (Gareau and Lima, 2010), SUMO2/3 localizes mainly in the nucleus (Supplementary Figure S1A)."
Evidence tracking, Biological System:Cultured neurons
Evidence tracking, Protein Targeting:Antibody (detection)
Evidence tracking, Experiment Assay:Super resolution
Annotator(s):Frank Koopmans (ORCID:0000-0002-4973-5732)
Guus Smit (ORCID:0000-0002-2286-1587)
Matthijs Verhage (ORCID:0000-0002-2514-0216)
Lab:Department of Functional Genomics, Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
Additional literature:SUMO2 was shown to conjugate to postsynaptic gephyrin/GPHN @ PMID:27819299

SUMO2 knockout impaired the maintenance of hippocampal LTP @ PMID:32910521

SUMO2 was shown to localize to PSD fractions @ PMID:14532281

SUMO3 was shown to conjugate presynaptic protein mGluR7/GRM7 @ PMID:26631532

SUMO1&3 were shown to conjugate to α-Synuclein @ PMID:25607946

SUMO1&2&3 were shown to conjugate to CASK @ PMID:18606847

SUMO1&2&3 were all detected in mass-spec of cortical synaptosomes with a unique peptide @ PMID:32439598

testing the specificity and sensitivity of twenty-four anti-SUMO MAbs towards monomeric and polymeric SUMO1-4 in dot-blots, immunoblots, immunofluorescence and immunoprecipitation @ PMID:36494414
SynGO annotation ID:5137
Dataset release (version):20231201
View annotation as GO-CAM model:Gene Ontology