Translational fidelity and growth of Arabidopsis require stress-sensitive diphthamide biosynthesis.

Diphthamide, a post-translationally modified histidine residue of eukaryotic TRANSLATION ELONGATION FACTOR2 (eEF2), is the human host cell-sensitizing target of diphtheria toxin. Diphthamide biosynthesis depends on the 4Fe-4S-cluster protein Dph1 catalyzing the first committed step, as well as Dph2 to Dph7, in yeast and mammals. Here we show that diphthamide modification of eEF2 is conserved in Arabidopsis thaliana and requires AtDPH1.

Abf1 Is an Essential Protein That Participates in Cell Cycle Progression and Subtelomeric Silencing in .

Accurate DNA replication and segregation is key to reproduction and cell viability in all organisms. Autonomously replicating sequence-binding factor 1 (Abf1) is a multifunctional protein that has essential roles in replication, transcription, and regional silencing in the model yeast . In the opportunistic pathogenic fungus , which is closely related to , these processes are important for survival within the host, for example, the regulation of transcription of virulence-related genes like those involved in adherence.

Chromatin Loop Formation Induced by a Subtelomeric Protosilencer Represses Genes in .

Adherence, an important virulence factor, is mediated by the (Epithelial Adhesin) genes in the opportunistic pathogen Expression of adhesin-encoding genes requires tight regulation to respond to harsh environmental conditions within the host. The majority of genes are localized in subtelomeric regions regulated by subtelomeric silencing, which depends mainly on Rap1 and the Sir proteins. adhesion to epithelial cells is primarily mediated by Epa1.

Npa3/ScGpn1 carboxy-terminal tail is dispensable for cell viability and RNA polymerase II nuclear targeting but critical for microtubule stability and function.

Genetic deletion of the essential GTPase Gpn1 or replacement of the endogenous gene by partial loss of function mutants in yeast is associated with multiple cellular phenotypes, including in all cases a marked cytoplasmic retention of RNA polymerase II (RNAPII). Global inhibition of RNAPII-mediated transcription due to malfunction of Gpn1 precludes the identification and study of other cellular function(s) for this GTPase. In contrast to the single Gpn protein present in Archaea, eukaryotic Gpn1 possesses an extension of approximately 100 amino acids at the C-terminal end of the GTPase domain.