Identifying biological pathways that underlie primordial short stature using network analysis
Identifying biological pathways that underlie primordial short stature using network analysis
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DOI：
10.1530/jme-14-0029
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发表时间：
2014-06-01
影响因子：
3.5
通讯作者：
Clayton, Peter E.
中科院分区：
文献类型：
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作者：
Hanson, Dan;Stevens, Adam;Clayton, Peter E.
CUL 7、OBSL 1和CCDC 8的突变导致泛素化紊乱，导致最常见的原始生长障碍之一，即3-M综合征。这种病症与i）异常p53功能，ii）GH和/或IGF 1抗性（其可能与信号分子再循环失败有关）和iii）细胞IGF 2缺陷有关。然而，可能联系这些异常产生生长限制的确切分子机制仍不清楚。在这项研究中，我们使用免疫沉淀/质谱和转录组学研究，以产生3-M的“相互作用组”，以确定关键的细胞通路和生物功能与生长失败中看到的3-M。我们鉴定了189个与CUL 7、OBSL 1和CCDC 8相互作用的蛋白质，并从中构建了包含176个蛋白质的网络。为了加强与3-M综合征的关联，将这些蛋白质与从与对照相比在3-M成纤维细胞中差异表达的基因产生的推断网络进行比较。这导致了最终的131个蛋白质的3-M网络，其中网络中最重要的生物学途径是mRNA剪接/加工。我们使用外源性胰岛素受体（INSR）小基因系统表明，外显子11的选择性剪接在具有CUL 7、OBSL 1和CCDC 8表达改变的HEK 293细胞和3-M成纤维细胞中显著改变。最终结果是3-M综合征中促有丝分裂INSR亚型表达减少。从这些初步数据中，我们假设无序的遍在蛋白化可能导致3-M中mRNA的异常剪接;然而，需要进一步的研究来确定这是否导致生长失败。
Mutations in CUL7, OBSL1 and CCDC8, leading to disordered ubiquitination, cause one of the commonest primordial growth disorders, 3-M syndrome. This condition is associated with i) abnormal p53 function, ii) GH and/or IGF1 resistance, which may relate to failure to recycle signalling molecules, and iii) cellular IGF2 deficiency. However the exact molecular mechanisms that may link these abnormalities generating growth restriction remain undefined. In this study, we have used immunoprecipitation/mass spectrometry and transcriptomic studies to generate a 3-M 'interactome', to define key cellular pathways and biological functions associated with growth failure seen in 3-M. We identified 189 proteins which interacted with CUL7, OBSL1 and CCDC8, from which a network including 176 of these proteins was generated. To strengthen the association to 3-M syndrome, these proteins were compared with an inferred network generated from the genes that were differentially expressed in 3-M fibroblasts compared with controls. This resulted in a final 3-M network of 131 proteins, with the most significant biological pathway within the network being mRNA splicing/processing. We have shown using an exogenous insulin receptor (INSR) minigene system that alternative splicing of exon 11 is significantly changed in HEK293 cells with altered expression of CUL7, OBSL1 and CCDC8 and in 3-M fibroblasts. The net result is a reduction in the expression of the mitogenic INSR isoform in 3-M syndrome. From these preliminary data, we hypothesise that disordered ubiquitination could result in aberrant mRNA splicing in 3-M; however, further investigation is required to determine whether this contributes to growth failure.