Severe Pelvic Endometriosis Involving the Rectum with Near Complete Bowel Obstruction: A Case Report

Endometriosis is a common gynecological disease among reproductive-age women that can result in chronic pain, severely decreased quality of life, and infertility. We present a case of a 44-year-old female with a known history of endometriosis who presented with constipation, decreased appetite, iron deficiency anemia, and unintentional weight loss for 6 months. Investigation with colonoscopy discovered a partially-obstructing mass in her proximal rectum and no evidence of malignancy on biopsy. The mass was subsequently removed during a combined robotic-assisted total hysterectomy with bilateral salpingo-ophorectomy and low anterior resection with reanastomosis. Surgical pathology determined that the mass was consistent with endometriosis and no malignancy was identified. This case calls attention to a unique manifestation of endometriosis and highlights the importance of maintaining a broad differential diagnosis while utilizing a multidisciplinary team in the management of a rectal mass in reproductive-age women

The F-BAR Domain of Rga7 Relies on a Cooperative Mechanism of Membrane Binding with a Partner Protein during Fission Yeast Cytokinesis

Summary: F-BAR proteins bind the plasma membrane (PM) to scaffold and organize the actin cytoskeleton. To understand how F-BAR proteins achieve their PM association, we studied the localization of a Schizosaccharomyces pombe F-BAR protein Rga7, which requires the coiled-coil protein Rng10 for targeting to the division site during cytokinesis. We find that the Rga7 F-BAR domain directly binds a motif in Rng10 simultaneously with the PM, and that an adjacent Rng10 motif independently binds the PM. Together, these multivalent interactions significantly enhance Rga7 F-BAR avidity for membranes at physiological protein concentrations, ensuring the division site localization of Rga7. Moreover, the requirement for the F-BAR domain in Rga7 localization and function in cytokinesis is bypassed by tethering an Rga7 construct lacking its F-BAR to Rng10, indicating that at least some F-BAR domains are necessary but not sufficient for PM targeting and are stably localized to specific cortical positions through adaptor proteins. : Liu et al. show that the Rga7 F-BAR domain binds an adaptor protein Rng10, which contains a second membrane-binding module, to enhance Rga7 membrane avidity and stabilize its membrane association. The authors reveal a mechanism by which F-BAR domains can achieve high-avidity binding with the plasma membrane. Keywords: BAR protein, cytokinesis, F-BAR, fission yeast, membrane binding, plasma membrane, Rga7, RhoGAP, Rng1