Functional Analysis of Subunit e of the F\u3csub\u3e1\u3c/sub\u3eF\u3csub\u3eo\u3c/sub\u3e-ATP Synthase of the Yeast \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e: Importance of the N-Terminal Membrane Anchor Region

Mitochondrial F1Fo-ATP synthase complexes do not exist as physically independent entities but rather form dimeric and possibly oligomeric complexes in the inner mitochondrial membrane. Stable dimerization of two F1Fo-monomeric complexes involves the physical association of two membrane-embedded Fo-sectors. Previously, formation of the ATP synthase dimeric-oligomeric network was demonstrated to play a critical role in modulating the morphology of the mitochondrial inner membrane. In Saccharomyces cerevisiae, subunit e (Su e) of the Fo-sector plays a central role in supporting ATP synthase dimerization. The Su e protein is anchored to the inner membrane via a hydrophobic region located at its N-terminal end. The hydrophilic C-terminal region of Su e resides in the intermembrane space and contains a conserved coiled-coil motif. In the present study, we focused on characterizing the importance of these regions for the function of Su e. We created a number of C-terminal-truncated derivatives of the Su e protein and expressed them in the Su e null yeast mutant. Mitochondria were isolated from the resulting transformant strains, and a number of functions of Su e were analyzed. Our results indicate that the N-terminal hydrophobic region plays important roles in the Su e-dependent processes of mitochondrial DNA maintenance, modulation of mitochondrial morphology, and stabilization of the dimer-specific Fo subunits, subunits g and k. Furthermore, we show that the C-terminal coiled-coil region of Su e functions to stabilize the dimeric form of detergent-solubilized ATP synthase complexes. Finally, we propose a model to explain how Su e supports the assembly of the ATP synthase dimers-oligomers in the mitochondrial membrane

Functional Analysis of Subunit e of the F(1)F(o)-ATP Synthase of the Yeast Saccharomyces cerevisiae: Importance of the N-Terminal Membrane Anchor Region

Mitochondrial F(1)F(o)-ATP synthase complexes do not exist as physically independent entities but rather form dimeric and possibly oligomeric complexes in the inner mitochondrial membrane. Stable dimerization of two F(1)F(o)-monomeric complexes involves the physical association of two membrane-embedded F(o)-sectors. Previously, formation of the ATP synthase dimeric-oligomeric network was demonstrated to play a critical role in modulating the morphology of the mitochondrial inner membrane. In Saccharomyces cerevisiae, subunit e (Su e) of the F(o)-sector plays a central role in supporting ATP synthase dimerization. The Su e protein is anchored to the inner membrane via a hydrophobic region located at its N-terminal end. The hydrophilic C-terminal region of Su e resides in the intermembrane space and contains a conserved coiled-coil motif. In the present study, we focused on characterizing the importance of these regions for the function of Su e. We created a number of C-terminal-truncated derivatives of the Su e protein and expressed them in the Su e null yeast mutant. Mitochondria were isolated from the resulting transformant strains, and a number of functions of Su e were analyzed. Our results indicate that the N-terminal hydrophobic region plays important roles in the Su e-dependent processes of mitochondrial DNA maintenance, modulation of mitochondrial morphology, and stabilization of the dimer-specific F(o) subunits, subunits g and k. Furthermore, we show that the C-terminal coiled-coil region of Su e functions to stabilize the dimeric form of detergent-solubilized ATP synthase complexes. Finally, we propose a model to explain how Su e supports the assembly of the ATP synthase dimers-oligomers in the mitochondrial membrane

Primary Care Clinician Perspectives on Patient Navigation to Improve Postpartum Care for Patients with Low Income.

Background: Birthing individuals experience significant physical and psychosocial transitions during the postpartum period. Despite amplified health needs, many individuals do not successfully transition from obstetric to primary care. Patient navigation provides a patient-centered solution that has been applied to other health care specialties resulting in improved care coordination and patient engagement for populations in greatest need. Our objective was to understand primary care clinician perspectives regarding the role of navigators in improving postpartum care for individuals with low income. Methods: In this qualitative investigation, we conducted focus groups with primary care clinicians from family and internal medicine specialties. Semistructured interview guides addressed clinician perceptions of navigator roles during the postpartum period and recommendations for navigator training. Focus group discussions were digitally recorded, transcribed, and analyzed via a constant comparative method. Results: Twenty-eight primary care clinicians, including 26 physicians and 2 advanced practice registered nurses, participated in 8 focus groups. Participants reported favorable attitudes toward implementation of a postpartum patient navigation program. Themes regarding useful navigation services included streamlining obstetric to primary care transition, enhancing visit effectiveness, creating personalized postpartum care, and providing patient- and clinician-focused education. Recommendations for navigator training included education on basic medical concerns that are common in the postpartum period, health information privacy and electronic health record use, health care systems, and community resources. Clinical Trial Registration number: NCT03922334. Conclusions: Primary care clinicians were highly receptive to the concept of patient navigation as a process to improve health in the postpartum period through enhanced care coordination and improved patient knowledge, engagement, and self-efficacy. Keywords: care coordination; clinician perspectives; patient navigation; postpartum care; primary care; transitions of care