The CELF1 RNA-Binding Protein Regulates Decay of Signal Recognition Particle mRNAs and Limits Secretion in Mouse Myoblasts.
The CELF1 RNA-Binding Protein Regulates Decay of Signal Recognition Particle mRNAs and Limits Secretion in Mouse Myoblasts.
复制标题
CELF1 RNA结合蛋白调节信号识别颗粒mRNA的衰减，并限制了小鼠成肌细胞中的分泌。
DOI：
10.1371/journal.pone.0170680
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Wilusz CJ
中科院分区：
文献类型：
--
作者：
Russo J;Lee JE;López CM;Anderson J;Nguyen TP;Heck AM;Wilusz J;Wilusz CJ
我们之前在与 RNA 结合蛋白 CELF1 相关的转录物中鉴定了几种编码分泌途径成分的 mRNA，包括信号识别颗粒 (SRP) 亚基 mRNA。通过对成肌细胞中与 CELF1 交联的 RNA 进行免疫沉淀，以及使用重组 CELF1 进行体外结合测定，我们现在提供了 CELF1 直接结合编码 SRP 每个亚基的 mRNA 的证据。此外，我们还确定了对照和 CELF1 敲低成肌细胞中 Srp 转录本的半衰期。我们的结果表明，CELF1 是 6 个 Srp 转录本中至少 5 个的去稳定剂，并且当 CELF1 耗尽时，SRP 蛋白的相对丰度会失去平衡。 CELF1敲除的成肌细胞表现出荧光素酶报告蛋白的分泌改变，并且其迁移和闭合伤口的能力受损，这与分泌的细胞外基质的缺陷一致。重要的是，当 SRP68 过度表达引起 SRP 亚基失衡时，也会观察到类似的伤口愈合缺陷。我们的研究支持包含 Srp mRNA 的 RNA 调节子的存在，该调节子由 CELF1 控制。一个暗示是，强直性肌营养不良中 CELF1 功能的改变可能通过分泌缺陷导致受影响肌肉的细胞外基质发生变化。
We previously identified several mRNAs encoding components of the secretory pathway, including signal recognition particle (SRP) subunit mRNAs, among transcripts associated with the RNA-binding protein CELF1. Through immunoprecipitation of RNAs crosslinked to CELF1 in myoblasts and in vitro binding assays using recombinant CELF1, we now provide evidence that CELF1 directly binds the mRNAs encoding each of the subunits of the SRP. Furthermore, we determined the half-lives of the Srp transcripts in control and CELF1 knockdown myoblasts. Our results indicate CELF1 is a destabilizer of at least five of the six Srp transcripts and that the relative abundance of the SRP proteins is out of balance when CELF1 is depleted. CELF1 knockdown myoblasts exhibit altered secretion of a luciferase reporter protein and are impaired in their ability to migrate and close a wound, consistent with a defect in the secreted extracellular matrix. Importantly, similar defects in wound healing are observed when SRP subunit imbalance is induced by over-expression of SRP68. Our studies support the existence of an RNA regulon containing Srp mRNAs that is controlled by CELF1. One implication is that altered function of CELF1 in myotonic dystrophy may contribute to changes in the extracellular matrix of affected muscle through defects in secretion.