Cultured embryonic stem cells (ESCs) can self-renew (the ability to go through numerous cycles of cell division while maintaining their undifferentiated, pluripotent states) and differentiate into one or more, cell type(s) under defined conditions, accompanied by exit from pluripotency. Transcriptional and epigenetic regulation of stem cells has been extensively investigated, including interconversion of differently caught pluripotency states in vitro. However, translational regulation is also important for stem cell fate. Although less studied, it is a fundamental mechanism for harnessing the full scope of stem cell biology, which provides essential concepts for its use in diagnostic and drug screening, and towards stem cell based therapeutic applications. My research with the microtubule-associated protein CLASP2 clearly links dynamic microtubules to protein trafficking, cellular signaling and, unexpectedly, to translational regulation. I have identified a novel function of CLASP in RNA-regulation through its interaction with the microtubule- and RNA-binding protein JAKMIP1. A growing number of signal effector proteins and partners thereof are found to interact with RNA, leading to my interest in JAKMIP1 function. Depletion of JAKMIP1 affects several pluripotency genes and impairs self-renewal and differentiation of ESCs. My work aims to address the mechanism by which JAKMIP1 controls translation in ESCs and the functional relevance of such regulation in maintaining stem cell identity. For this, I will engineer the JAKMIP1 locus in ESCs using CRISPR/Cas9 technology. These cells will then be used for novel high-throughput analyses, including Ribo-SEQ, and iCLIP, and also advanced fluorescence microscopy to study protein behavior and interactions in living cells.