The State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, #7 Jinsui Road, Guangzhou, Guangdong 510230, China.
Curr Mol Med. 2018;18(8):533-541. doi: 10.2174/1566524019666190112132103.
Protein Sumoylation is one of the most important and prevalent posttranscriptional modification. Increasing evidence have shown that the SENPs (sentrin/SUMOspecific proteases) are critical for steady-state levels of SUMO modification of target proteins, and protein de-sumoylation modulates a great diversity of biological processes including transcription, development, differentiation, neuroprotection, as well as pathogenesis. In the vertebrate eye, we and others have previously shown that sumoylation participated in the differentiation of major ocular tissues including retina and lens. However, the biological significance of seven SENP enzymes: SENP1 to 3 and SENP5 to 8 have not be fully investigated in the ocular tissues.
The 5 major ocular cell lines were cultured in Dulbecco's modified Eagle's medium (DMEM) containing fetal bovine serum (FBS) or rabbit serum (RBS) and 1% Penicillin- Streptomycin. The mRNA levels were analysed with qRT-PCR. The protein levels were determined with western blot analysis and quantitated with Image J.
At the mRNA level, all SENPs were highly expressed in retina, and much reduced expression patterns in cornea, lens epithelium and lens fiber. At the protein level, SENP1 to -3, and SENP6 were highly abundant in cornea, while SENP5, SENP7 and SENP8 were enriched in retina, and these SENPs were relatively less abundant in lens tissues.
Our results for the first time established the differentiation expression patterns of the 7 de-sumoylation enzymes (SENPs), which provides a basis for further investigation of protein desumoylation functions in vertebrate eye.
蛋白质 SUMO 化修饰是最重要、最普遍的转录后修饰之一。越来越多的证据表明，SENPs（sentrin/SUMO 特异性蛋白酶）对于靶蛋白 SUMO 修饰的稳态水平至关重要，蛋白质去 SUMO 化修饰调节包括转录、发育、分化、神经保护以及发病机制在内的多种生物学过程。在脊椎动物眼中，我们和其他人之前已经表明 SUMO 化参与了主要眼部组织（包括视网膜和晶状体）的分化。然而，七种 SENP 酶（SENP1 至 3 和 SENP5 至 8）在眼部组织中的生物学意义尚未得到充分研究。
培养 5 种主要的眼部细胞系，使用含有胎牛血清（FBS）或兔血清（RBS）和 1%青霉素-链霉素的 Dulbecco 改良 Eagle 培养基（DMEM）。使用 qRT-PCR 分析 mRNA 水平。使用 Western blot 分析测定蛋白水平，并使用 Image J 进行定量。
在 mRNA 水平，所有 SENP 在视网膜中高度表达，而在角膜、晶状体上皮和晶状体纤维中表达模式降低。在蛋白质水平，SENP1 至 -3 和 SENP6 在角膜中含量丰富，而 SENP5、SENP7 和 SENP8 在视网膜中丰富，这些 SENP 在晶状体组织中相对较少。
我们的研究结果首次建立了 7 种去 SUMO 化酶（SENPs）的分化表达模式，为进一步研究脊椎动物眼中蛋白质去 SUMO 化功能提供了基础。
