Genome-wide maps of RNA Pol III subunits POLR3C, POLR3G, and PLOR3GL in ES-E14TG2a and primary MEF cells

ABSTRACT: Mammalian cells contain two isoforms of RNA Polymerase III (Pol III) that differ in only a single subunit, with POLR3G in one form and the related POLR3GL in the other form. Previous research indicates that POLR3G and POLR3GL are differentially expressed, with POLR3G expression being largely restricted to embryonic stem cells (ESCs) and tumor cells in contrast to the ubiquitously expressed POLR3GL. To date, the functional differences between these two subunits remain largely unexplored, especially in vivo. Here, we show that POLR3G and POLR3GL containing Pol III complexes bind the same target genes and assume the same functions both in vitro and in vivo and, to a certain degree, can compensate for each other in vivo. Moreover, an observed defect in the differentiation ability of POLR3G knockout ESCs can be rescued by exogenous expression of POLR3GL. Interestingly, POLR3G knockout mice die at a very early embryonic stage, whereas POLR3GL knockout mice complete embryonic development without noticeable defects but die at about 3 weeks after birth with signs of both general growth defects and potential cerebellum-related neuronal defects. The different phenotypes of the knockout mice likely reflect differential expression levels of POLR3G and POLR3GL across developmental stages and between tissues and insufficient amounts of total Pol III in vivo.

ORGANISM(S): Mus musculus

PROVIDER: GSE143969 | GEO | 2020/01/22

REPOSITORIES: GEO