Cordycepin interferes with 3′ end formation in yeast independently of its potential to terminate RNA chain elongation

Abstract

Cordycepin (39 deoxyadenosine) is a biologically active compound that, when incorporated during RNA synthesis in vitro, provokes chain termination due to the absence of a 39 hydroxyl moiety. We were interested in the effects mediated by this drug in vivo and analyzed its impact on RNA metabolism of yeast. Our results support the view that cordycepin-triphosphate (CoTP) is the toxic component that is limiting cell growth through inhibition of RNA synthesis. Unexpectedly, cordycepin treatment modulated 39 end heterogeneity of ACT1 and ASC1 mRNAs and rapidly induced extended transcripts derived from CYH2 and NEL025c loci. Moreover, cordycepin ameliorated the growth defects of poly(A) polymerase mutants and the pap1-1 mutation neutralized the effects of the drug on gene expression. Our observations are consistent with an epistatic relationship between poly(A) polymerase function and cordycepin action and suggest that a major mode of cordycepin activity reduces 39 end formation efficiency independently of its potential to terminate RNA chain elongation. Finally, chemical-genetic profiling revealed genome-wide pathways linked to cordycepin activity and identified novel genes involved in poly(A) homeostasis.

Inhibition of polyadenylation reduces inflammatory gene induction

“…In addition, termination and cleavage defects are observed on three genes in cordycepintreated cells (Fig. 6), similar to effects previously observed in vitro (Ryner and Manley 1987) and in yeast (Holbein et al 2009). It is therefore likely that the effect of cordycepin on gene expression is at least in part mediated by a stabilization of an intermediate 39 processing complex (Zarkower and Wickens 1987), leading either to a depletion of factors or to a block in the normal exchange of factors on the 39 end of the pre-mRNA.…”

“…The cordycepin-arrested cleavage complex has been shown to contain factors involved in other aspects of the regulation of gene expression, including transcriptional regulators and mRNA export factors (Shi et al 2009). Mutations in chromatin remodeling factors including SWI/SNF components and subunits of the SAGA complex have indeed been shown to increase cordycepin sensitivity in yeast, indicating that gene-specific effects of cordycepin may be linked to differences in chromatin structure (Holbein et al 2009). In addition, one of the NFkB subunits, c-Rel, has been reported to interact with PAPa (Bouwmeester et al 2004).…”

The Maternal-to-Zygotic Transition in Higher Plants

“…Actinomycin D binds to the DNA transcription initiation complex and interferes with elongation of the RNA chain by RNA polymerase (Sobell, 1985). Cordycepin, a derivative of adenosine, is incorporated into RNA and inhibits transcription elongation because of the absence of a hydroxyl moiety at the 3 0 position (Holbein et al, 2009). In combination with a well-established embryonic isolation method and a culture system, 20 μg/mL actinomycin D and 40 μg/mL cordycepin were added to a semi-in vivo zygote culture system, and the inhibitory effects of the drugs on RNA transcription confirmed by reverse transcriptionpolymerase chain reaction (RT-PCR) analysis.…”

“…Actinomycin D can stimulate DNA topoisomerase-induced DNA cleavage and impair DNA replication (Guy & Taylor, 1978;Wassermann et al, 1990). Moreover, cordycepin not only inhibits chain termination, but also exerts a very strong effect on mRNA polyadenylation in certain strains (Holbein et al, 2009). Although these side effects are known, the inhibitors have been successfully used in many experiments.…”

A Role for CF1A 3′ End Processing Complex in Promoter-Associated Transcription

“…At least three subunits of this complex (Rna14, Rna15 and Pcf11) associate with both ends of a transcriptionally engaged gene [18], [36]. CF1A subunits exhibit genetic and physical interaction with several promoter-bound factors that include both the general transcription factors and gene specific factors [16], [18], [33], [37]–[41]. Furthermore, CF1A subunits are also required for juxtaposition of the promoter and terminator regions to form a looped gene structure [18].…”