Dissecting the developmental roles of Pol II‐associated proteins through the stomatal pores

Abstract

Dissecting the developmental roles of Pol II-associated proteins through the stomatal pores In eukaryotes, RNA polymerase II (Pol II, RNAP II or RPB) is the RNA polymerase that transcribes DNA into messenger RNA (mRNA). During transcription initiation, the multi-subunit Pol II complex and general transcription factors (GTFs) are recruited to the core promoter to form a pre-initiation complex (PIC) before driving transcription (Carrera & Treisman, 2008). Recent studies in yeast and mammals have identified additional protein factors associated with Pol II, including four RNA polymerase IIassociated proteins (RPAP1, RPAP2, RPAP3 and RPAP4) (Jeronimo et al., 2004). These RPAPs play vital roles in the assembly, nuclear import and function of Pol II (Wild & Cramer, 2012). In the model plant Arabidopsis, homologs of these RPAPs are also present and their cellular and developmental roles in plants are beginning to be revealed (Table 1). Similar to their animal counterparts, these plant RPAPs share multiple interactions with each other and are essential in the assembly of Pol II, Pol IV, and Pol V (Muñoz et al., 2017; Li et al., 2018). In addition, the plant RPAPs are involved in diverse developmental processes, particularly in promoting cell differentiation (Lahmy et al., 2007; Sanmart ın et al., 2011; Sotta et al., 2016). In this issue of New Phytologist, Chen et al. (2021; pp. 171-189) demonstrate that the Arabidopsis homolog of RPAP2, RPAP2 IYO MATE (RIMA), mediates the nuclear import of the Pol II complex, interacts with the stomatal lineage-specific transcription factors and is essential for restraining division and establishing cell identity in the stomatal lineage, providing insights into these evolutionarily conserved proteins.

On Sun Lau

“…For example, Chen et al . (2021), which we had the pleasure to write a commentary on (see Zhou & Lau, 2021) and also Han et al . (2022).…”

“…I am also pleased to see there are more detailed molecular studies on stomatal development in the journal. For example, Chen et al (2021), which we had the pleasure to write a commentary on (see Zhou & Lau, 2021) and also Han et al (2022).…”