Developmental Neurobiology Group, Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604, Republic of Singapore.
Mol Cell Biochem. 2010 Jun;339(1-2):191-9. doi: 10.1007/s11010-010-0385-x. Epub 2010 Feb 9.
PHR protein family consists of C. elegan Rpm-1/Drosophila Highwire/Zebrafish Esrom/Mouse Phr-1/Human Pam. Esrom is required for correct neurites exiting the paused state at intermediate targets as well as pteridine synthesis. This study reports the identification and characterization of two novel Esrom splice variants, named splice variants 2 (splicing out 5' 24 bp of exon 17) and 3 (splicing out 5' 24 bp of exons 17 and 18). Polypeptides encoded by 5' 24 bp of exons 17 and 18 are part of basic amino-acid-rich region inside Esrom RCC1-like domain (RLD). These two splice variants maintain the whole protein reading frame and alternative exons usage patterns are conserved with mammal. At different developmental stages and adult zebrafish tissues, abundances of these splice variants are different. Importantly, by yeast two-hybrid screen and confocal colocalization analysis, it was found that alternative splicing of exon 18 regulates Esrom RLD interaction with kinesin family member 22 and G protein beta-subunit 1. Taken together, these results suggest that Esrom RLD functions are regulated by alternative splicing at temporal and spatial-specific manner.
PHR 蛋白家族包括 C. elegans Rpm-1/果蝇 Highwire/斑马鱼 Esrom/小鼠 Phr-1/人 Pam。Esrom 对于正确的神经突退出暂停状态以及蝶呤合成在中间靶点是必需的。本研究报告了两种新的 Esrom 剪接变体的鉴定和特征，分别命名为剪接变体 2（剪接去除外显子 17 的 5' 24 个碱基）和 3（剪接去除外显子 17 和 18 的 5' 24 个碱基）。由外显子 17 和 18 的 5' 24 个碱基编码的多肽是 Esrom RCC1 样结构域（RLD）内碱性氨基酸丰富区域的一部分。这两种剪接变体保持整个蛋白质阅读框，并且替代外显子的使用模式与哺乳动物保守。在不同的发育阶段和成年斑马鱼组织中，这些剪接变体的丰度不同。重要的是，通过酵母双杂交筛选和共聚焦共定位分析，发现外显子 18 的选择性剪接调节了 Esrom RLD 与驱动蛋白家族成员 22 和 G 蛋白β亚基 1 的相互作用。总之，这些结果表明 Esrom RLD 功能受时空特异性的选择性剪接调节。
