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Regulation of postsynaptic RapGAP SPAR by Polo-like kinase 2 and the SCFbeta-TRCP ubiquitin ligase in hippocampal neurons.

ABSTRACT: The ubiquitin-proteasome pathway (UPP) regulates synaptic function, but little is known about specific UPP targets and mechanisms in mammalian synapses. We report here that the SCF(beta-TRCP) complex, a multisubunit E3 ubiquitin ligase, targets the postsynaptic spine-associated Rap GTPase activating protein (SPAR) for degradation in neurons. SPAR degradation by SCF(beta-TRCP) depended on the activity-inducible protein kinase Polo-like kinase 2 (Plk2). In the presence of Plk2, SPAR physically associated with the SCF(beta-TRCP) complex through a canonical phosphodegron. In hippocampal neurons, disruption of the SCF(beta-TRCP) complex by overexpression of dominant interfering beta-TRCP or Cul1 constructs prevented Plk2-dependent degradation of SPAR. Our results identify a specific E3 ubiquitin ligase that mediates degradation of a key postsynaptic regulator of synaptic morphology and function.

SUBMITTER: Ang XL

PROVIDER: S-EPMC2570879 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature

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Regulation of postsynaptic RapGAP SPAR by Polo-like kinase 2 and the SCFbeta-TRCP ubiquitin ligase in hippocampal neurons.

Ang Xiaolu L XL Seeburg Daniel P DP Sheng Morgan M Harper J Wade JW

The Journal of biological chemistry 20080822 43

The ubiquitin-proteasome pathway (UPP) regulates synaptic function, but little is known about specific UPP targets and mechanisms in mammalian synapses. We report here that the SCF(beta-TRCP) complex, a multisubunit E3 ubiquitin ligase, targets the postsynaptic spine-associated Rap GTPase activating protein (SPAR) for degradation in neurons. SPAR degradation by SCF(beta-TRCP) depended on the activity-inducible protein kinase Polo-like kinase 2 (Plk2). In the presence of Plk2, SPAR physically ass ...[more]

PMID: 18723513

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