Arabidopsis C-terminal domain phosphatase-like 1 and 2 are essential Ser-5-specific C-terminal domain phosphatases. Academic Article uri icon

abstract

  • Transcription and mRNA processing are regulated by phosphorylation and dephosphorylation of the C-terminal domain (CTD) of RNA polymerase II, which consists of tandem repeats of a Y(1)S(2)P(3)T(4)S(5)P(6)S(7) heptapeptide. Previous studies showed that members of the plant CTD phosphatase-like (CPL) protein family differentially regulate osmotic stress-responsive and abscisic acid-responsive transcription in Arabidopsis thaliana. Here we report that AtCPL1 and AtCPL2 specifically dephosphorylate Ser-5 of the CTD heptad in Arabidopsis RNA polymerase II, but not Ser-2. An N-terminal catalytic domain of CPL1, which suffices for CTD Ser-5 phosphatase activity in vitro, includes a signature DXDXT acylphosphatase motif, but lacks a breast cancer 1 CTD, which is an essential component of the fungal and metazoan Fcp1 CTD phosphatase enzymes. The CTD of CPL1, which contains two putative double-stranded RNA binding motifs, is essential for the in vivo function of CPL1 and includes a C-terminal 23-aa signal responsible for its nuclear targeting. CPL2 has a similar domain structure but contains only one double-stranded RNA binding motif. Combining mutant alleles of CPL1 and CPL2 causes synthetic lethality of the male but not the female gametes. These results indicate that CPL1 and CPL2 exemplify a unique family of CTD Ser-5-specific phosphatases with an essential role in plant growth and development.

published proceedings

  • Proc Natl Acad Sci U S A

altmetric score

  • 3

author list (cited authors)

  • Koiwa, H., Hausmann, S., Bang, W. Y., Ueda, A., Kondo, N., Hiraguri, A., ... Shuman, S.

citation count

  • 93

complete list of authors

  • Koiwa, Hisashi||Hausmann, Stéphane||Bang, Woo Young||Ueda, Akihiro||Kondo, Naoko||Hiraguri, Akihiro||Fukuhara, Toshiyuki||Bahk, Jeong Dong||Yun, Dae-Jin||Bressan, Ray A||Hasegawa, Paul M||Shuman, Stewart

publication date

  • October 2004