Kalidas Ramamoorthy M, Raja Subramanian Elaiya, Mydeen Sheik Abdul Kader Nagoor Meeran, Samuel Selvan Christyraj Johnson Retnaraj, Durairaj Selvan Christyraj Jackson, Nino Gopi D, Palanichelvam Karuppaiah, Vaithi Arumugaswami, Sudhakar Sivasubramaniam
Department of Biotechnology, Manonmaniam Sundaranar University, Tirunelveli-627012, Tamilnadu, India.
Department of Biotechnology, Kalasalingam University, Krishnankoil-626126, Tamilnadu, India.
Cell Biol Int. 2015 Sep;39(9):1036-43. doi: 10.1002/cbin.10479. Epub 2015 May 1.
Lamin A is an intermediate filament protein found in most of the differentiated vertebrate cells but absent in stem cells. It shapes the skeletal frame structure beneath the inner nuclear membrane of the cell nucleus. As there are few studies of the expression of lamin A in invertebrates, in the present work, we have analyzed the sequence, immunochemical conservation and expression pattern of lamin A protein in the earthworm Eudrilus eugeniae, a model organism for tissue regeneration. The expression of lamin A has been confirmed in E. eugeniae by immunoblot. Its localization in the nuclear membrane has been observed by immunohistochemistry using two different rabbit anti-sera raised against human lamin A peptides, which are located at the C-terminus of the lamin A protein. These two antibodies detected 70 kDa lamin A protein in mice and a single 65 kDa protein in the earthworm. The Oct-4 positive undifferentiated blastemal tissues of regenerating earthworm do not express lamin A, while the Oct-4 negative differentiated cells express lamin A. This pattern was also confirmed in the earthworm prostate gland. The present study is the first evidence for the immunochemical identification of lamin A and Oct-4 in the earthworm. Along with the partial sequence obtained from the earthworm genome, the present results suggest that lamin A protein and its expression pattern is conserved from the earthworm to humans.
核纤层蛋白A是一种中间丝蛋白，存在于大多数分化的脊椎动物细胞中，但在干细胞中不存在。它塑造了细胞核内核膜下方的骨骼框架结构。由于关于无脊椎动物中核纤层蛋白A表达的研究较少，在本研究中，我们分析了核纤层蛋白A在赤子爱胜蚓（一种组织再生的模式生物）中的序列、免疫化学保守性和表达模式。通过免疫印迹法已证实核纤层蛋白A在赤子爱胜蚓中表达。使用针对位于核纤层蛋白A蛋白C末端的人核纤层蛋白A肽段产生的两种不同兔抗血清，通过免疫组织化学观察到其在核膜中的定位。这两种抗体在小鼠中检测到70 kDa的核纤层蛋白A蛋白，在蚯蚓中检测到单一的65 kDa蛋白。再生蚯蚓中Oct-4阳性的未分化胚基组织不表达核纤层蛋白A，而Oct-4阴性的分化细胞表达核纤层蛋白A。这种模式在蚯蚓前列腺中也得到了证实。本研究是在蚯蚓中对核纤层蛋白A和Oct-4进行免疫化学鉴定的首个证据。连同从蚯蚓基因组获得的部分序列，目前的结果表明核纤层蛋白A蛋白及其表达模式从蚯蚓到人类都是保守的。
