海马神经元中，苏氨酸840和丝氨酸845位点的α-氨基-3-羟基-5-甲基-4-异恶唑丙酸（AMPA）受体GluA1亚基的基础磷酸化水平。

Basal levels of AMPA receptor GluA1 subunit phosphorylation at threonine 840 and serine 845 in hippocampal neurons.

作者信息

Babiec Walter E, Guglietta Ryan, O'Dell Thomas J

机构信息

Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA.

Interdepartmental Ph.D. Program for Neuroscience at UCLA, Los Angeles, California 90095, USA.

出版信息

Learn Mem. 2016 Mar 15;23(4):127-33. doi: 10.1101/lm.040675.115. Print 2016 Apr.

Dephosphorylation of AMPA receptor (AMPAR) GluA1 subunits at two sites, serine 845 (S845) and threonine 840 (T840), is thought to be involved in NMDA receptor-dependent forms of long-term depression (LTD). Importantly, the notion that dephosphorylation of these sites contributes to LTD assumes that a significant fraction of GluA1 subunits are basally phosphorylated at these sites. To examine this question, we used immunoprecipitation/depletion assays to estimate the proportion of GluA1 subunits basally phosphorylated at S845 and T840. Although dephosphorylation of S845 is thought to have a key role in LTD, our results indicate that few GluA1 subunits in hippocampal neurons are phosphorylated at this site. In contrast, ∼50% of GluA1 subunits are basally phosphorylated at T840, suggesting that dephosphorylation of this site can contribute to the down-regulation of AMPAR-mediated synaptic transmission in LTD.

α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体（AMPAR）的GluA1亚基在两个位点，即丝氨酸845（S845）和苏氨酸840（T840）处的去磷酸化，被认为与N-甲基-D-天冬氨酸受体（NMDA受体）依赖形式的长时程抑制（LTD）有关。重要的是，这些位点的去磷酸化有助于LTD这一观点假定相当一部分GluA1亚基在这些位点处于基础磷酸化状态。为了研究这个问题，我们使用免疫沉淀/去除测定法来估计在S845和T840处基础磷酸化的GluA1亚基的比例。尽管S845的去磷酸化被认为在LTD中起关键作用，但我们的结果表明，海马神经元中很少有GluA1亚基在该位点被磷酸化。相比之下，约50%的GluA1亚基在T840处处于基础磷酸化状态，这表明该位点的去磷酸化可能有助于LTD中AMPAR介导的突触传递的下调。