RT Journal
A1 Lin, Zhanmin
A1 Wu, Bin
A1 Paul, Maarten W.
A1 Li, Ka Wan
A1 Yao, Yao
A1 Smal, Ihor
A1 Proietti Onori, Martina
A1 Hasanbegovic, Hana
A1 Bezstarosti, Karel
A1 Demmers, Jeroen
A1 Houtsmuller, Adriaan B.
A1 Meijering, Erik
A1 Hoebeek, Freek E.
A1 Schonewille, Martijn
A1 Smit, August B.
A1 Gao, Zhenyu
A1 De Zeeuw, Chris I.
T1 Protein Phosphatase 2B Dual Function Facilitates Synaptic Integrity and Motor Learning
JF The Journal of Neuroscience 
JO The Journal of Neuroscience 
YR 2021 
FD June 30 
VO 41 
IS 26 
SP 5579 
OP 5594 
DO 10.1523/JNEUROSCI.1741-20.2021 
UL http://www.jneurosci.org/content/41/26/5579.abstract 
AB Protein phosphatase 2B (PP2B) is critical for synaptic plasticity and learning, but the molecular mechanisms involved remain unclear. Here we identified different types of proteins that interact with PP2B, including various structural proteins of the postsynaptic densities (PSDs) of Purkinje cells (PCs) in mice. Deleting PP2B reduced expression of PSD proteins and the relative thickness of PSD at the parallel fiber to PC synapses, whereas reexpression of inactive PP2B partly restored the impaired distribution of nanoclusters of PSD proteins, together indicating a structural role of PP2B. In contrast, lateral mobility of surface glutamate receptors solely depended on PP2B phosphatase activity. Finally, the level of motor learning covaried with both the enzymatic and nonenzymatic functions of PP2B. Thus, PP2B controls synaptic function and learning both through its action as a phosphatase and as a structural protein that facilitates synapse integrity.SIGNIFICANCE STATEMENT Phosphatases are generally considered to serve their critical role in learning and memory through their enzymatic operations. Here, we show that protein phosphatase 2B (PP2B) interacts with structural proteins at the synapses of cerebellar Purkinje cells. Differentially manipulating the enzymatic and structural domains of PP2B leads to different phenotypes in cerebellar learning. We propose that PP2B is crucial for cerebellar learning via two complementary actions, an enzymatic and a structural operation.