TZAP: A telomere-associated protein involved in telomere length control.

Telomeres are found at the end of chromosomes and are important for chromosome stability. Here we describe a specific telomere-associated protein: TZAP (telomeric zinc finger-associated protein). TZAP binds preferentially to long telomeres that have a low concentration of shelterin complex, competing with the telomeric-repeat binding factors TRF1 and TRF2.

Put a RING on it: regulation and inhibition of RNF8 and RNF168 RING finger E3 ligases at DNA damage sites.

RING (Really Interesting New Gene) domain-containing E3 ubiquitin ligases comprise a large family of enzymes that in combination with an E2 ubiquitin-conjugating enzyme, modify target proteins by attaching ubiquitin moieties. A number of RING E3s play an essential role in the cellular response to DNA damage highlighting a crucial contribution for ubiquitin-mediated signaling to the genome surveillance pathway. Among the RING E3s, RNF8 and RNF168 play a critical role in the response to double stranded breaks, one of the most deleterious types of DNA damage.

A snapshot of the physical and functional wiring of the Eps15 homology domain network in the nematode.

Protein interaction modules coordinate the connections within and the activity of intracellular signaling networks. The Eps15 Homology (EH) module, a protein-protein interaction domain that is a key feature of the EH-network, was originally identified in a few proteins involved in endocytosis and vesicle trafficking, and has subsequently also been implicated in actin reorganization, nuclear shuttling, and DNA repair. Here we report an extensive characterization of the physical connections and of the functional wirings of the EH-network in the nematode.

A two-step mechanism for TRF2-mediated chromosome-end protection.

Mammalian telomeres repress DNA-damage activation at natural chromosome ends by recruiting specific inhibitors of the DNA-damage machinery that form a protective complex termed shelterin. Within this complex, TRF2 (also known as TERF2) has a crucial role in end protection through the suppression of ATM activation and the formation of end-to-end chromosome fusions. Here we address the molecular properties of TRF2 that are both necessary and sufficient to protect chromosome ends in mouse embryonic fibroblasts.

Novel physiological modulation of the Pu promoter of TOL plasmid: negative regulatory role of the TurA protein of Pseudomonas putida in the response to suboptimal growth temperatures.

From crude protein extracts of Pseudomonas putida KT2440, we identified a small protein, TurA, able to bind to DNA fragments bearing the entire Pu promoter sequence of the TOL plasmid. The knock-out inactivation of the turA gene resulted in enhanced transcription initiation from the Pu promoter, initially suggesting a negative regulatory role of TurA on Pu expression. Ectopic expression of TurA both in P.