Chinese Scientists Found A Critical Role of PIWI/piRNA in Translation Activation during Sperm Formation
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Time: 2019-12-16
A team of scientists led by Drs. LIU Mofang at the Center for Excellence in Molecular Cell Science-Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, ZHOU Yu at Wuhan University, and SHI Huijuan at Shanghai Institute of Planned Parenthood Research, Fudan University Reproduction and Development Institution, have found a critical role of PIWI/piRNA in translation activation during Sperm Formation. This work entitled “A Translation-Activating Function of MIWI/piRNA during Mouse Spermiogenesis” was online published in Cell on Dec 12, 2019. The work was collaborated with Drs. LI Dangsheng, LI Jinsong and FU Xiangdong.
The spermatid development, termed as Spermiogenesis, in mammals undergoes a series of dramatic morphological changes, which is programmed by a series of highly orchestrated regulatory events in gene expression at each developmental step. Due to chromatin compaction during the course of spermatid elongation, transcription becomes gradually inhibited during spermiogenesis and then completely ceased later on. Thus, the program of spermiogenesis relies on gene products that are transcribed earlier and stored in translationally
inert messenger ribonucleoproteins (mRNPs) until needed for translation. This phenomenon, known as uncoupling between transcription and translation, is a unique feature of gene regulation during spermiogenesis, which has been one of the major mysteries in understanding the germ cell development program. The evolutionarily conserved Piwi proteins belong to the Piwi clade of
the Argonaute family, each of which is specifically expressed during the development of animal germline. Piwi proteins are known to enlist germline-specific Piwi-interacting RNAs (piRNAs) to suppress transposable elements and protect the integrity of the genome in germ cells.
Peng Dai, Xin Wang, Lantao Gou, Zhitong Li, Ze Wen, Zonggui Chen and their colleagues, under the supervision of Drs. LIU Mofang, ZHOU Yu and SHI Huijuan,
unexpectedly discover that the mouse PIWI (MIWI)/piRNA same machinery is also responsible for activating translation of a subset of spermiogenic mRNAs to coordinate with morphological transformation into spermatozoa. Such action requires specific base-pairing interactions of piRNAs with target mRNAs in their 3¢UTRs, which activates translation through coupling with
cis-acting AU-rich elements to nucleate the formation of a MIWI/piRNA/eIF3f/HuR super-complex in a developmental stage-specific manner. These findings reveal a critical role of the piRNA system in translation activation, which they show is functionally required for spermatid development.
This study was supported by the grants from the Chinese Academy of Sciences, National Natural Science Foundation of China, Ministry of Science and Technology, and Science and Technology Commission of Shanghai Municipality.
Reference: https://www.sciencedirect.com/science/article/pii/S0092867419312784?via%3Dihub
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