Epidermal progenitors suppress GRHL3-mediated differentiation through intronic polyadenylation promoted by CPSF-HNRNPA3 collaboration

• Published in: Nature communications 2021-01, Vol.12 (1), p.448-448, Article 448
• Main Authors: Chen, Xin, Lloyd, Sarah M., Kweon, Junghun, Gamalong, Giovanni M., Bao, Xiaomin
• Format: Article
• Language: English
• Subjects: 38; 38/109; 38/23; 38/39; 38/89; 45; 49; 59; 631/136; 631/136/142; 631/136/2441; 631/337; 64; Binding; Cell Differentiation - genetics; Cell Self Renewal - genetics; Cleavage And Polyadenylation Specificity Factor - genetics; Cleavage And Polyadenylation Specificity Factor - metabolism; Cooperativity; CRISPR; CRISPR-Cas Systems - genetics; Differentiation; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Epidermis; Gene expression; Gene Expression Regulation; Gene Knockdown Techniques; Gene Knockout Techniques; Genetic screening; HEK293 Cells; Heterogeneous-Nuclear Ribonucleoprotein Group A-B - genetics; Heterogeneous-Nuclear Ribonucleoprotein Group A-B - metabolism; Humanities and Social Sciences; Humans; Introns - genetics; Keratinocytes; Keratinocytes - physiology; multidisciplinary; Myc protein; Polyadenylation; Polyadenylation - genetics; Primary Cell Culture; Proteins; Re-Epithelialization - genetics; Ribonucleic acid; RNA; RNA-binding protein; Science; Science (multidisciplinary); Stem Cells - physiology; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-20674-3

In self-renewing somatic tissue such as skin epidermis, terminal differentiation genes must be suppressed in progenitors to sustain regenerative capacity. Here we show that hundreds of intronic polyadenylation (IpA) sites are differentially used during keratinocyte differentiation, which is accompanied by downregulation of the Cleavage and Polyadenylation Specificity Factor (CPSF) complex. Sustained CPSF expression in undifferentiated keratinocytes requires the contribution from the transcription factor MYC. In keratinocytes cultured in undifferentiation condition, CSPF knockdown induces premature differentiation and partially affects dynamically used IpA sites. These sites include an IpA site located in the first intron of the differentiation activator GRHL3. CRISPR knockout of GRHL3 IpA increased full-length GRHL3 mRNA expression. Using a targeted genetic screen, we identify that HNRNPA3 interacts with CPSF and enhances GRHL3 IpA. Our data suggest a model where the interaction between CPSF and RNA-binding proteins, such as HNRNPA3, promotes site-specific IpA and suppresses premature differentiation in progenitors. Suppression of terminal differentiation is essential for epidermal progenitor maintenance. Here, the authors show that intronic polyadenylation is dynamically regulated by the cooperation between CPSF and RNA-binding proteins to influence epidermal differentiation gene expression.