Department of Physiology & Biochemistry, University of Malta, Msida, Malta.
Bioessays. 2010 Dec;32(12):1077-89. doi: 10.1002/bies.201000088. Epub 2010 Oct 15.
Gemins 2-8 and Unr-interacting protein (UNRIP) are intimate partners of the survival motor neuron (SMN) protein, which is the determining factor for the neuromuscular disorder spinal muscular atrophy (SMA). The most documented role of SMN, Gemins and UNRIP occurs within the large macromolecular SMN complex and involves the cytoplasmic assembly of spliceosomal uridine-rich small nuclear ribonucleoproteins (UsnRNPs), a housekeeping process critical in all cells. Several reports detailing alternative functions for SMN in either motor neurons or skeletal muscles may, however, hold the answer to the extreme neuromuscular tissue specificity observed in SMA. Recent discoveries indicate that collaboration between SMN and Gemins also extends to these non-canonical functions, hence raising the possibility that mutations in Gemin genes may be the cause of unlinked neuromuscular hereditary syndromes. This review evaluates the functions of Gemins and UNRIP inside the SMN complex and discusses whether these less notorious SMN complex members are capable of acting independently of SMN.
Gemins2-8 和 Unr-interacting protein (UNRIP) 是运动神经元存活蛋白 (SMN) 的亲密伙伴,SMN 蛋白是神经肌肉疾病脊髓性肌萎缩症 (SMA) 的决定因素。SMN、Gemins 和 UNRIP 的最有文献记载的作用发生在大型大分子 SMN 复合物内,并涉及剪接体富含尿嘧啶的小核核糖核蛋白 (UsnRNPs) 的细胞质组装,这是所有细胞中关键的管家过程。然而,有几个详细描述 SMN 在运动神经元或骨骼肌中替代功能的报告,可能解答了在 SMA 中观察到的极度神经肌肉组织特异性的问题。最近的发现表明,SMN 和 Gemins 之间的协作也扩展到这些非规范功能,因此,Gemins 基因突变可能是无关联的神经肌肉遗传性综合征的原因。这篇综述评估了 Gemins 和 UNRIP 在 SMN 复合物中的功能,并讨论了这些不太知名的 SMN 复合物成员是否能够独立于 SMN 发挥作用。