Casein kinase and monopolin subunit; regulates diverse events including vesicular traffic, DNA repair, the CVT pathway, ribosomal subunit biogenesis, cohesin cleavage, monopolar attachment of sister kinetochores at MI and exit from MII; autophosphorylation regulates elongator-dependent tRNA modifications; binds the RNAPII CTD; phosphorylates COPII coat subunits; antagonizes phosphatase Sit4p; inhibits Crz1p and calcineurin signaling; phosphorylates Dsn1p; functional ortholog of human CK1epsilon