The OTUD5-UBR5 complex regulates FACT-mediated transcription at damaged chromatin.

Timely stalling and resumption of RNA polymerases at damaged chromatin are actively regulated processes. Prior work showed an importance of FACT histone chaperone in such process. Here we provide a new role of OTUD5 deubiquitinase in the FACT-dependent process. Through a DUB RNAi screen, we found OTUD5 as a specific stabilizer of the UBR5 E3 ligase. OTUD5 localizes to DNA double strand breaks (DSBs), interacts with UBR5 and represses the RNA Pol II elongation and RNA synthesis. OTUD5 co-localizes and interacts with the FACT component SPT16 and antagonizes the histone H2A deposition at DSB lesions. OTUD5 interacts with UBR5 and SPT16 independently through two distinct regions, and both interactions are necessary for arresting the Pol II elongation at lesions. These analyses suggested that the catalytic (through UBR5 stabilization) as well as scaffolding (through FACT binding) activities of OTUD5 are involved in the FACT-dependent transcription. We found that a cancer-associated missense mutation within the OTUD5 Ubiquitin Interacting Motif (UIM) abrogates the FACT association and the Pol II arrest, providing a possible link between the transcriptional regulation and tumor suppression. Our work establishes OTUD5 as a new regulator of the DNA damage response, and provides an insight into the FACT-dependent transcription at damaged chromatin.

Impact of screw length and screw quantity on reverse total shoulder arthroplasty glenoid fixation for 2 different sizes of glenoid baseplates.

BACKGROUND: Little guidance exists regarding the minimum screw length and screw quantity necessary to achieve fixation in reverse total shoulder arthroplasty (rTSA); to that end, this study quantified the displacement of 2 different sizes of glenoid baseplates using multiple different screw lengths and quantities of screws in a low-density polyurethane bone-substitute model. METHODS: Testing of rTSA glenoid loosening was conducted according to ASTM F 2028-17. To independently evaluate the impact of screw quantity and screw length on rTSA glenoid fixation for 2 different sizes of glenoid baseplates, baseplates were constructed using 2 screws, 4 screws, or 6 screws (with the latter being used for the larger baseplate only) with 3 different poly-axial locking compression screw lengths. RESULTS: Both sizes of glenoid baseplates remained well fixed after cyclic loading regardless of screw length or screw quantity. Baseplates with 2 screws had significantly greater displacement than baseplates with 4 or 6 screws. No differences were observed between baseplates with 4 screws and those with 6 screws (used for the larger baseplate). Both sizes of baseplates with 18-mm screws had significantly greater displacement than baseplates with 30- or 46-mm screws. For larger baseplates, those with 30-mm screws had significantly greater displacement than those with 46-mm screws in the superior-inferior direction. DISCUSSION: For the 2 different sizes of baseplates tested in this study, rTSA glenoid fixation was impacted by both screw quantity and screw length. Irrespective of screw quantity, longer screws showed significantly better fixation. Irrespective of screw length, the use of more screws showed significantly better fixation, up to a point, as the use of more than 4 screws showed no incremental benefit. Finally, longer screws can be used as a substitute for additional fixation if it is not feasible to use more screws.

Cromomicosis por cladophialophora carrionii: características citogenéticas básicas: comunicación preliminar / Chromomycosis due to cladophilophora carrionii: basic cytogenetic characters: preliminary report

Hay estudios de diversa indole sobre pacientes con cromomicosis cladophialophora carrionni del foco endémico del estado Falcón (Venezuela), pero no ha sido estudiada la genética de ellos. Demostrar alteraciones citogenéticas relacionadas con la enfermedad y comparar su frecuencia en pobladores afectados y no afectados por esta enfermedad. Fueron seleccionados 11 pacientes consanguíneos con diagnóstico o historia de cromomicosis para el grupo de casos y 13 controles no consanguíneos, sin historia ni diagnóstico de la enfermedad. Los estudios citogenéticos se realizaron en muestras se sangre periférica. Ciento por ciento de los casos presentó alteraciones citogenéticas y no se encontraron en ninguno de los controles. Estas alteraciones fueron: ruptura de cromátides en 82 por ciento, pérdidas cromosómicas en 17 por ciento, ganancias cromosómicas en 7 por ciento y los cromososmas 1 y 6 fueron los más frecuentemente asociados a polimorfismo. Se demostró la presencia de alteraciones citogenéticas en 100 por ciento de los casos mientras que éstas no se encontraron en los controles. El patrón encontrado se puede asociar con otras enfermedades autosómicas recesivas por lo que esta probabilidad debe ser estudiada para definir si es el gatillo o la condición poligénica que permite la mayor suceptibilidad a la enfermedad fúngica