TABLE 4.

Transcriptional CDKs in metazoans.

Cyclin‐dependent kinase	Binding partner	Roles in cell cycle	Roles in transcription	Selected additional roles
CDK7	Cyclin H	CAK activity (for CDK1/2/4/6) (Bisteau et al., 2013; Fisher, 2005, 2012; Larochelle et al., 1998, 2007; Merrick et al., 2008; Schachter & Fisher, 2013) Required for cell cycle progression (Ganuza et al., 2012; Larochelle et al., 1998, 2007; Olson et al., 2019; Wallenfang & Seydoux, 2002)	CAK activity (for CDK9/12/13) (Fisher, 2012; Larochelle et al., 2012; Rimel et al., 2020) Part of TFIIH complex, important for early steps of pol II transcription (Fisher, 2005; Glover‐Cutter et al., 2009; Larochelle et al., 2012; Maldonado & Reinberg, 1995; Rimel & Taatjes, 2018; Roy et al., 1994) CTD kinase (S5, S7) (Akhtar et al., 2009; Fisher, 2005; Glover‐Cutter et al., 2009; Pinhero et al., 2004; Roy et al., 1994; Wallenfang & Seydoux, 2002)	Implicated in DNA damage and repair pathways (Rimel & Taatjes, 2018)
CDK8	Cyclin C	Inhibits CAK activity (Akoulitchev et al., 2000; Szilagyi & Gustafsson, 2013) Promotes cell‐cycle commitment through β‐catenin pathway (Firestein et al., 2008; Szilagyi & Gustafsson, 2013) Promotes G2/M transition (Philip et al., 2018; Xu et al., 2015) Promotes cell cycle arrest at R point through p21 activation (Donner et al., 2007; Porter et al., 2012; Szilagyi & Gustafsson, 2013) Maintains quiescence of VPC in C. elegans (Clayton et al., 2008)	Part of mediator complex (Dannappel et al., 2019; Fant & Taatjes, 2019; Galbraith et al., 2010; Luyties & Taatjes, 2022; Poss et al., 2013; D. Wu, Zhang, et al., 2021) CTD kinase (S5) (Pinhero et al., 2004; Rickert et al., 1999) Can upregulate and downregulate transcription (Galbraith et al., 2010) Inhibits TFIIH to downregulate transcription (Akoulitchev et al., 2000) Promotes expression of hypoxia‐inducible genes after recruitment by HIF1A (Galbraith et al., 2013)	Acts as sensitiser for apoptosis (MacKeigan et al., 2005) Regulates Myc to maintain stem cell pluripotency (Adler et al., 2012) Essential for early embryogenesis (mouse) (Westerling et al., 2007) Implicated in DNA damage and repair pathways (Poss et al., 2016)
CDK19	Cyclin C		Part of mediator complex (Dannappel et al., 2019; Fant & Taatjes, 2019; Luyties & Taatjes, 2022)	Implicated in DNA damage and repair pathways (Poss et al., 2016)
CDK9	Cyclin T	Necessary for cell cycle recovery after replication stress (D. S. Yu et al., 2010) Upregulates cell proliferation through PABIR1 and PCNP (Tellier et al., 2022) Gets recruited to chromatin to promote progression through G1 (Anshabo et al., 2021; Cai et al., 2006; Storch & Cordes, 2016; Yang et al., 2008)	Part of P‐TEFb complex, important for pol II release from the promoter‐proximal pause and elongation (Anshabo et al., 2021; Bacon & D'Orso, 2019; Egloff, 2021; Jonkers & Lis, 2015; Luo et al., 2012; Parua et al., 2018) CTD kinase (S2, T4, S5, S7) (Eick & Geyer, 2013; Heidemann et al., 2013; Pinhero et al., 2004; Zaborowska et al., 2016) Targets transcriptional repressor Rb (Graña et al., 1994; Simone et al., 2002; Storch & Cordes, 2016)	Implicated in DNA damage and repair pathways (Anshabo et al., 2021)
CDK12	Cyclin K	Phosphorylates cyclin E1 to stimulate formation of pre‐replicative complex, therefore controlling G1/S progression (Lei et al., 2018; S. Liang et al., 2020; Manavalan et al., 2019) Controls translation of mitotic‐regulator gene mRNAs (Choi et al., 2019) Promotes G2/M transition (Blazek et al., 2011; Geng et al., 2019; H. R. Chen et al., 2017; Schecher et al., 2017) Downregulates G2/M transition in breast cancer cells (Quereda et al., 2019)	Required for efficient elongation and pre‐mRNA 3′ end formation (Bösken et al., 2014; Choi et al., 2020; Eifler et al., 2015; Fan et al., 2020; Lui et al., 2018; Quereda et al., 2019; Tellier et al., 2020) CTD kinase (S2, S5) (Bartkowiak et al., 2010; Blazek et al., 2011; Bösken et al., 2014; Cheng et al., 2012; Tellier et al., 2020) Implicated in regulation of splicing (H. H. Chen et al., 2006; K. Liang, Gao, et al., 2015; S. Liang et al., 2020; Panzeri et al., 2013) Inhibition severely affects expression of long DNA Damage Response (DDR) genes (Blazek et al., 2011; Choi et al., 2020; Dubbury et al., 2018; Krajewska et al., 2019) Negatively regulates differentiation (Dai et al., 2012)	Implicated in DNA damage response (Blazek et al., 2011; H. R. Chen et al., 2017; Choi et al., 2020; Dubbury et al., 2018; Fan et al., 2020; Juan et al., 2015; Krajewska et al., 2019; K. Liang, Gao, et al., 2015; S. Liang et al., 2020; Manavalan et al., 2019; Quereda et al., 2019; Tellier et al., 2020) Promotes neurogenesis (H. R. Chen et al., 2017) Essential for early embryogenesis (mouse) (Juan et al., 2015)
CDK13	Cyclin K	Promotes G2/M transition in gastric cancer cells (Z. Wu, Wang, et al., 2021) Downregulates G2/M transition in breast cancer cells (Quereda et al., 2019)	Required for efficient elongation and pre‐mRNA 3′ end formation (Fan et al., 2020; K. Liang, Gao, et al., 2015; Quereda et al., 2019) CTD kinase (S2, S5) (Greifenberg et al., 2016) Regulates expression of snoRNA genes (K. Liang, Gao, et al., 2015) Implicated in regulation of splicing (H. H. Chen et al., 2007; K. Liang, Gao, et al., 2015; Panzeri et al., 2013) Activates RNA surveillance pathway (Insco et al., 2023) Negatively regulates differentiation (Dai et al., 2012) Increases splicing of HIV‐1 mRNA (Berro et al., 2008)	Implicated in DNA damage response (Fan et al., 2020) Implicated in growth signaling pathways (Fan et al., 2020; Greifenberg et al., 2016) Promotes cell survival in breast cancer cells (Quereda et al., 2019) Promotes neurogenesis (H. R. Chen et al., 2017)