Saha Monalee, Ingraham Susan E, Carpenter Ashley, Robinson Melissa, McHugh Kelsey E, Singh Sunita, Robinson Michael L, McHugh Kirk M
Center for Cell and Developmental Biology, Research Institute, Nationwide Children's Hospital, Columbus, Ohio 43205, USA.
J Urol. 2009 Aug;182(2):766-75. doi: 10.1016/j.juro.2009.03.079. Epub 2009 Jun 18.
Although the importance of myocardin in smooth muscle development is well established, many tissue specific intricacies of smooth muscle differentiation remain to be determined. We characterized myocardin expression in the developing and adult bladder to identify potential tissue specific differences that may have a role in detrusor smooth muscle development.
Reverse transcriptase and quantitative polymerase chain reaction were done to determine myocardin expression in the mouse and human bladder vs various other tissues. Sequence analysis was done to confirm the genomic location of the various polymerase chain reaction products.
Exonic profiling of the mouse myocardin gene identified a series of unique myocardin splice variants derived from a novel 305 bp exon between exons 2 and 3 of the previously identified myocardin gene. Each variant showed a differential pattern of expression in the mouse and primary protein sequences suggested a unique function for each myocardin variant identified. Identical myocardin splice variants were also observed in the human bladder as well as a unique human specific exon 12 myocardin splice variant that was not observed in the mouse.
Identifying a series of unique myocardin splice variants that are differentially expressed in the bladder, and other muscle and nonmuscle tissues provides a potential molecular platform for mediating many unique tissue specific functions associated with the myocardin transcriptional program.
尽管心肌素在平滑肌发育中的重要性已得到充分证实，但平滑肌分化的许多组织特异性复杂机制仍有待确定。我们对发育中和成年膀胱中的心肌素表达进行了表征，以确定可能在逼尿肌平滑肌发育中起作用的潜在组织特异性差异。
进行逆转录和定量聚合酶链反应，以确定小鼠和人膀胱与其他各种组织中的心机素表达。进行序列分析以确认各种聚合酶链反应产物的基因组位置。
小鼠心肌素基因的外显子分析鉴定出一系列独特的心肌素剪接变体，这些变体源自先前鉴定的心肌素基因外显子2和3之间一个新的305 bp外显子。每个变体在小鼠中表现出不同的表达模式，并且一级蛋白质序列表明所鉴定的每个心肌素变体具有独特的功能。在人膀胱中也观察到相同的心肌素剪接变体，以及在小鼠中未观察到的独特的人特异性外显子12心肌素剪接变体。
鉴定出一系列在膀胱以及其他肌肉和非肌肉组织中差异表达的独特心肌素剪接变体，为介导与心肌素转录程序相关的许多独特组织特异性功能提供了一个潜在的分子平台。
