| Annotated protein: | Serine/threonine-protein kinase MARK2 (EC 2.7.11.1) (EC 2.7.11.26) (ELKL motif kinase 1) (EMK-1) (MAP/microtubule affinity-regulating kinase 2). Gene symbol: MARK2. Taxonomy: Rattus norvegicus (Rat). Uniprot ID: O08679 |
| antibody wiki: | |
| SynGO gene info: | SynGO data @ MARK2 |
| Ontology domain: | Biological Process |
| SynGO term: | regulation of postsynapse organization (GO:0099175) |
| Synapse type(s): | hippocampus, glutamatergic |
| Annotated paper: | Wu Q, et al. "The polarity protein partitioning-defective 1 (PAR-1) regulates dendritic spine morphogenesis through phosphorylating postsynaptic density protein 95 (PSD-95" J Biol Chem. 2012 Aug 31;287(36):30781-8 PMID:22807451 |
| Figure(s): | fig 1c,e-h & 2-5 |
| Annotation description: | From Results section: "To see if PAR-1 plays a role in spine morphogenesis, we began by depleting endogenous PAR-1 in cultured hippocampal neurons using shRNAs." (...) "As shown in Fig. 1c, expression of MARK2/PAR-1b shRNA1 caused a spine dysgenesis phenotype in which the spines were elongated with smaller spine heads. Similar results were obtained with PAR-1b shRNA2 (data not shown). The mean length of spines was 2.10 +- 0.74 m in PAR-1b knockdown neurons versus 0.96 +- 0.31 m in control neurons. The mean width of spines was 0.48 +- 0.21 m in PAR-1b knockdown neurons versus 0.75 +- 0.29 m in control neurons (p 0.001 for spine length and width compared with control neurons) (Fig. 1, e and f)." "we expressed kinase-dead PAR-1b (PAR-1b(T175A,S179A)) in PAR-1c-depleted neurons. Unlike wild-type PAR-1b, kinasedead PAR-1b was unable to rescue the spine formation defects (Fig. 1, c, g, and h)." (...) "This shows that the kinase activity of PAR-1 is necessary for spine morphogenesis." "When we expressed the kinase-dead PAR-1b(T175A,S179A) mutant in hippocampal neurons, we observed a significant decrease in the density of dendritic spines compared with control neurons expressing an empty vector (Fig. 2). Interestingly, a significant decrease in spine density was also observed in neurons overexpressing wild-type PAR-1b (Fig. 2). This suggests that a critical level of PAR-1 kinase activity is essential for proper spine morphogenesis." (...) "the T562E mutant is an inactivated version of PAR-1b, whereas the T562A mutant is active. Both mutants showed a significant decrease in spine density compared with control neurons (Fig. 2), which further shows that the level of PAR-1 kinase activity is critical for spine morphogenesis and that either too much or too little PAR-1 kinase activity is detrimental." "Both wild-type and kinase-dead PAR-1b, but not an unrelated protein, were able to interact with PSD-95 (Fig. 3a)" "As shown in Fig. 3b, robust serine phosphorylation was observed when wild-type PAR-1b was incubated with the wild-type SH3 and guanylate kinase domains, but not with the S561A mutant. Furthermore, minimal phosphorylation was observed when kinase-dead PAR-1b was used as the kinase source (Fig. 3b) or when PAR-1b was denatured (data not shown). This suggests that PAR-1 can phosphorylate PSD-95 at Ser-561." "As shown in Fig. 4a, both mutants S561A and S561D localized well to synapses, similar to their wild-type counterpart. This shows that Ser-561 does not regulate synaptic targeting of PSD-95." "Expression of wild-type PSD-95 or PSD95(S561D) did not significantly affect the density of dendritic spines. Interestingly, however, the expression of the S561A mutant significantly reduced spine density (Fig. 4, b and c), suggesting that Ser-561 regulates spine morphogenesis." "We expressed kinase-dead PAR-1b(T175A,S179A) along with different PSD-95 constructs in hippocampal neurons. As shown in Fig. 5, only the S561D mutant was able to rescue the defect of kinase-dead PAR-1b, suggesting that PSD-95 Ser-561 phosphorylation is downstream of PAR-1 in spine morphogenesis. Taken together, these results show an important role for PAR-1 in dendritic spine morphogenesis through phosphorylating PSD-95 at Ser-561." |
| Evidence tracking, Biological System: | Cultured neurons |
| Evidence tracking, Protein Targeting: | RNAi / shRNA Over-expression Antibody (detection) |
| Evidence tracking, Experiment Assay: | Confocal IP + WB/MSMS |
| Annotator(s): | Rita Reig-Viader (ORCID:0000-0002-6893-6177) Àlex Bayés (ORCID:0000-0002-5265-6306) |
| Lab: | Molecular Physiology of the Synapse Laboratory, Biomedical Research Institute Sant Pau, 08025 Barcelona, Spain and and Universitat Autnoma de Cerdanyola del Valls, Spain Barcelona, 08193 Bellaterra |
| SynGO annotation ID: | 3079 |
| Dataset release (version): | 20231201 |
| View annotation as GO-CAM model: |  |