Interaction and localization of the retinitis pigmentosa protein RP2 and NSF in retinal photoreceptor cells.

RP2 is a ubiquitously expressed protein encoded by a gene associated with X-linked retinitis pigmentosa (XLRP), a retinal degenerative disease that causes severe vision loss. Previous in vitro studies have shown that RP2 binds to ADP ribosylation factor-like 3 (Arl3) and activates its intrinsic GTPase activity, but the function of RP2 in the retina, and in particular photoreceptor cells, remains unclear. To begin to define the role of RP2 in the retina and XLRP, we have conducted biochemical studies to identify proteins in retinal cell extracts that interact with RP2. Here, we show that RP2 interacts with N-ethylmaleimide sensitive factor (NSF) in retinal cells as well as cultured embryonic kidney (HEK293) cells by mass spectrometry-based proteomics and biochemical analysis. This interaction is mediated by the N-terminal domain of NSF. The E138G and DeltaI137 mutations of RP2 known to cause XLRP abolished the interaction of RP2 with the N-terminal domain of NSF. Immunofluorescence labeling studies further showed that RP2 colocalized with NSF in photoreceptors and other cells of the retina. Intense punctate staining of RP2 was observed close to the junction between the inner and outer segments beneath the connecting cilium, as well as within the synaptic region of rod and cone photoreceptors. Our studies indicate that RP2, in addition to serving as a regulator of Arl3, interacts with NSF, and this complex may play an important role in membrane protein trafficking in photoreceptors and other cells of the retina.

The future of general surgery training: A Canadian resident nationwide Delphi consensus statement.

BACKGROUND: Several models have been introduced to improve and restructure surgical training, but continued barriers exist. Residents are uniquely positioned to offer perspective on practical challenges and needs of reformatting surgical education. This study aimed to establish a nationwide, Delphi consensus statement on the perceptions of Canadian residents regarding the future of general surgery training. METHODS: Canadian general surgery residents participated in a moderated focus group using the Nominal Group Technique to discuss early subspecialization, competency-based medical education, and transition to practice. Qualitative verbal data were transcribed, categorized into themes, and synthesized into recommendation statements. During an iterative Delphi survey, resident leaders ranked each statement on a 5-point Likert scale of agreement. The survey was terminated once consensus was achieved (≥2 survey rounds and Cronbach's α ≥ 0.80). RESULTS: A total of 66 statements were synthesized by 16 members of the Canadian Association of General Surgeons Resident Committee. A total of 49 residents participated in the Delphi consensus, which was achieved after 2 voting rounds (Cronbach's α = 0.93). Participants agreed that (1) residency should focus on achieving standardized competencies and milestones based on resident ability to meet specific measurable metrics, (2) early streaming should be offered after "core" milestones and competencies have been achieved, and (3) an explicit period should allow transition-to-independent practice with tailored rotations, greater autonomy, and resident-run clinics. We identified 10 barriers to competency-based medical education implementation. CONCLUSION: A nationwide consensus regarding the future of surgical training was established among current residents. These findings can inform and help implement guidelines and national curricula that meet the needs of the trainee and address the many challenges they face during their training.