mRNA Cap Methylation in Pluripotency and Differentiation

作者：Grasso Laura; Suska Olga; Davidson Lindsay; Gonatopoulos Pournatzis Thomas; Williamson Ritchie; Wasmus Lize; Wiedlich Simone; Peggie Mark; Stavridis Marios P; Cowling Victoria H^*

来源：Cell Reports, 2016, 16(5): 1352-1365.

DOI：10.1016/j.celrep.2016.06.089

The mRNA cap recruits factors essential for transcript processing and translation initiation. We report that regulated mRNA cap methylation is a feature of embryonic stem cell (ESC) differentiation. Expression of the mRNA cap methyltransferase activating subunit RAM is elevated in ESCs, resulting in high levels of mRNA cap methylation and expression of a cohort of pluripotency-associated genes. During neural differentiation, RAM is suppressed, resulting in repression of pluripotency-associated factors and expression of a cohort of neural-associated genes. An established requirement of differentiation is increased ERK1/2 activity, which suppresses pluripotency-associated genes. During differentiation, ERK1/2 phosphorylates RAM serine-36, targeting it for ubiquitination and proteasomal degradation, ultimately resulting in changes in gene expression associated with loss of pluripotency. Elevated RAM expression also increases the efficiency of fibroblast reprogramming. Thus, the mRNA cap emerges as a dynamic mark that instructs change in gene expression profiles during differentiation and reprogramming.

• 出版日期2016-8-2