Alternative splice variants of MYH9.
Alternative splice variants of MYH9.
复制标题
MYH9 的替代剪接变体。
DOI：
10.1089/dna.2007.0661
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发表时间：
2008
影响因子：
3.1
通讯作者：
Mhatre,AnandN
中科院分区：
文献类型：
--
作者：
Li,Yan;Lalwani,AnilK;Mhatre,AnandN
MYH9 编码 II 类非肌肉肌球蛋白重链 A (NMHC-IIA)，一种广泛表达的 1960 个氨基酸多肽，翻译分子量为 220 kDa。编码 NMHC-IIA 的相对较多的外显子 (40) 以及已记录的其两种亚型 MYH10 和 MYH14 的剪接变体，强烈表明 MYH9 存在替代剪接。在当前的研究中，我们在重链的两个独立区域中对 Myh9 剪接变体进行有针对性的搜索，这两个区域编码环 1 和环 2 子域，其中已鉴定出 MYH10 和 MYH14 剪接变体中的替代外显子。使用两种策略进行剪接变体搜索：直接在可疑外显子上扩增，或通过对可疑内含子区域的保守序列分析鉴定出的推定剪接变体进行扩增。在环 1 内，仅使用保守序列分析鉴定了 12 和 41 个核苷酸的两个单独插入。位于内含子 4 内的每一个插入都会导致变异转录物的过早终止。在环 2 内，使用两种策略均鉴定出 63 个核苷酸长的框内插入。该插入与 Myh10 对应物长度相同，显示出 65% 的序列同一性，但与本研究中鉴定的 Myh14 转录本内的 123 个核苷酸长的插入有很大不同。 Myh9 的环 1 和环 2 变体均在耳蜗中检测到，其中后者在大脑中含量最多。具有提前终止密码子的环1变体的表达可能反映了调节Myh9表达的另一种模式，而环2变体的保守序列和选择性表达突出了其潜在的生物学重要性。
MYH9encodes a class II nonmuscle myosin heavy chain-A (NMHC-IIA), a widely expressed 1960 amino acid polypeptide, with a translated molecular weight of 220 kDa. The relatively large number of exons (40) that encode NMHC-IIA and the splice variants that have been documented for its two isoforms,MYH10andMYH14, strongly suggest existence of alternative splicing forMYH9. In the current study, we perform a targeted search forMyh9splice variants in two separate regions of the heavy chain that encode loop 1 and loop 2 subdomains within which alternative exons inMYH10andMYH14splice variants have been identified. The splice variant search was conducted using two strategies: amplification across the suspected exons directly or by amplification of putative splice variants identified through conserved sequence analysis of suspected intronic regions. Within loop 1, two separate insertions of 12 and 41 nucleotides were identified using conserved sequence analysis only. Each of these insertions, located within intron 4, resulted in premature termination of the variant transcript. Within loop 2, a 63-nucleotide-long in-frame insertion was identified using both strategies. The insertion is identical in length and displays 65% sequence identity with itsMyh10counterpart, but differs greatly from the 123-nucleotide-long insertion withinMyh14transcript identified in this study. Both loop 1 and loop 2 variants ofMyh9were detected in the cochlea, with the latter being most abundant in the brain. Expression of loop 1 variants with premature termination codon may reflect an alternate mode of regulatingMyh9expression, while the conserved sequence and selective expression of the loop 2 variant highlight its potential biological importance.