EIF3D Safeguards the Homeostasis of Key Signaling Pathways in Human Primed Pluripotency

Pluripotent stem cell identities such as differentiation and infinite proliferation have long been decoded in the frameworks of transcription factor networks, epigenomes, and signal transduction, yet unclear and fragmented. However, directing attention toward translation regulation, the bridge between these events promises to provide new insights into previously unexplained mechanisms. Functional screening led to the discovery that EIF3D maintains primed pluripotency via selective translation regulation. The loss of EIF3D unbalanced the pluripotency-associated signaling pathways, disrupting primed pluripotency. Furthermore, we found that EIF3D safeguards robust proliferation by managing the translation of multiple p53 regulators that maintain low p53 activity in the undifferentiated state. Therefore, this study provides a paradigm for selective translation regulation that defines the primed pluripotent stem cell identity. We utilized on genome-wide functional screening using the CRISPR interference (CRISPRi) platform with Human Genome-wide CRISPRi-v2 Libraries (https://www.addgene.org/pooled-library/weissman-human-crispri-v2/). Set A were used for d0_1, d0_2, d8_1, d8_2 and d16_1 and Set B were used for d8_3, d16_2, d0_3 and d16_3. We collected samples from day 0 and day 16 after doxycycline (Dox, WAKO) treatment.