TY  - JOUR
A1  - Schmitt, Dominique
A1  - Funk, Natalia
A1  - Blum, Robert
A1  - Asan, Esther
A1  - Andersen, Lill
A1  - Rülicke, Thomas
A1  - Sendtner, Michael
A1  - Buchner, Erich
T1  - Initial characterization of a Syap1 knock-out mouse and distribution of Syap1 in mouse brain and cultured motoneurons
JF  - Histochemistry and Cell Biology
N2  - Synapse-associated protein 1 (Syap1/BSTA) is the mammalian homologue of Sap47 (synapse-associated protein of 47 kDa) in Drosophila. Sap47 null mutant larvae show reduced short-term synaptic plasticity and a defect in associative behavioral plasticity. In cultured adipocytes, Syap1 functions as part of a complex that phosphorylates protein kinase B alpha/Akt1 (Akt1) at Ser\(^{473}\) and promotes differentiation. The role of Syap1 in the vertebrate nervous system is unknown. Here, we generated a Syap1 knock-out mouse and show that lack of Syap1 is compatible with viability and fertility. Adult knock-out mice show no overt defects in brain morphology. In wild-type brain, Syap1 is found widely distributed in synaptic neuropil, notably in regions rich in glutamatergic synapses, but also in perinuclear structures associated with the Golgi apparatus of specific groups of neuronal cell bodies. In cultured motoneurons, Syap1 is located in axons and growth cones and is enriched in a perinuclear region partially overlapping with Golgi markers. We studied in detail the influence of Syap1 knockdown and knockout on structure and development of these cells. Importantly, Syap1 knockout does not affect motoneuron survival or axon growth. Unexpectedly, neither knockdown nor knockout of Syap1 in cultured motoneurons is associated with reduced Ser\(^{473}\) or Thr\(^{308}\) phosphorylation of Akt. Our findings demonstrate a widespread expression of Syap1 in the mouse central nervous system with regionally specific distribution patterns as illustrated in particular for olfactory bulb, hippocampus, and cerebellum.
KW  - Protein kinase B
KW  - Spinal Muscular-arthropy
KW  - Rictor-mTOR complex
KW  - Neurotrophic factors
KW  - Plasma-membrane
KW  - Axon growth
KW  - SAP47 gene
KW  - Phosphorylation
KW  - Drosophilia
KW  - Cells
KW  - BSTA
KW  - Viability
KW  - Brain
KW  - Syap1 localization
KW  - Glutamatergic synapses
KW  - PKB/Akt phosphorylation
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-187258
VL  - 146
IS  - 4
ER  - 
TY  - JOUR
A1  - von Collenberg, Cora R.
A1  - Schmitt, Dominique
A1  - Rülicke, Thomas
A1  - Sendtner, Michael
A1  - Blum, Robert
A1  - Buchner, Erich
T1  - An essential role of the mouse synapse-associated protein Syap1 in circuits for spontaneous motor activity and rotarod balance
JF  - Biology Open
N2  - Synapse-associated protein 1 (Syap1) is the mammalian homologue of synapse-associated protein of 47 kDa (Sap47) in Drosophila. Genetic deletion of Sap47 leads to deficiencies in short-term plasticity and associative memory processing in flies. In mice, Syap1 is prominently expressed in the nervous system, but its function is still unclear. We have generated Syap1 knockout mice and tested motor behaviour and memory. These mice are viable and fertile but display distinct deficiencies in motor behaviour. Locomotor activity specifically appears to be reduced in early phases when voluntary movement is initiated. On the rotarod, a more demanding motor test involving control by sensory feedback, Syap1-deficient mice dramatically fail to adapt to accelerated speed or to a change in rotation direction. Syap1 is highly expressed in cerebellar Purkinje cells and cerebellar nuclei. Thus, this distinct motor phenotype could be due to a so-far unknown function of Syap1 in cerebellar sensorimotor control. The observed motor defects are highly specific since other tests in the modified SHIRPA exam, as well as cognitive tasks like novel object recognition, Pavlovian fear conditioning, anxiety-like behaviour in open field dark-light transition and elevated plus maze do not appear to be affected in Syap1 knockout mice.
KW  - Syap1 knockout
KW  - Motor behaviour
KW  - Associative learning
KW  - Fear conditioning
KW  - Object recognition
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201986
N1  - PDF includes: Correction: An essential role of the mouse synapse-associated protein Syap1 in circuits for spontaneous motor activity and rotarod balance - February 15, 2020. Biology Open (2020) 9, bio048942. doi:10.1242/bio.048942
VL  - 8
ER  -