The Gobel Lab

Overview

Cellular asymmetry (polarity) is a requirement for the formation and function of organs in all multi-cellular organisms, and the loss of polarity is a hallmark of cancer. The Gobel Lab investigates new polarity cues identified in genome-scale screens carried out in the genetic model organism Caenorhabditis elegans. These molecular cues - all conserved in humans - are expected to provide insight into the still unanswered question of how cells specify polarity in the tissue context and how this process is linked to growth control in developing organs. C. elegans uniquely allows the visual observation (live) and genetic dissection of how single cells break symmetry within developing tissues and organs.

Research Projects

Our non-biased screens on multicellular (intestinal) and unicellular (excretory canal) C. elegans tubulogenesis have identified previously unknown roles of essential (lethal) genes in lumenogenesis and polarity. The analysis of these genes by genetic, cell-biological, biochemical, and optogenetic means has uncovered intracellular processes required to assemble asymmetries in single cells in developing mucosal epithelia. These findings challenge the current view that cells break symmetry at their periphery, the cell cortex. Multiple genes identified in our genome-scale screens are still awaiting analysis and are expected to further delineate a new molecular pathway for polarized membrane biogenesis.

1. Cell polarity and lumenogenesis in multicellular tubular epithelia.
   We identified multiple vesicle-based and cytoskeletal molecules whose characterization revealed that the directionality of vesicular trafficking is regulated in polarizing cells and operates upstream of membrane-based polarity cues (e.g., the partitioning-defective PARs). Our projects use genetic and optogenetic means to characterize this new mechanism of symmetry breaking where membrane polarity is specified by the asymmetric insertion of the nascent apical domain.
2. Cell polarity and lumenogenesis in unicellular tubular epithelia.
   We have identified biomechanical aspects of capillary-like intracellular lumenogenesis, such as a morphogenetic role of aquaporin-dependent hydrostatic pressure and a tensile peri-lumenal intermediate-filament lattice. We are currently exploring antagonistic functions of single V-ATPase subunit genes, also identified in our tubulogenesis screens, in intracellular apical membrane and lumen biogenesis in this single-cell tube.
3. Cell polarity and growth control.
   We are investigating a link between loss of polarity and hyper-proliferation in the C. elegans embryonic intestine - an observation made during the analysis of our polarity screens. We would like to further characterize the identified genes that promise to provide insight into the still enigmatic association of polarity and growth control.
4. Technical approaches for developmental molecular genetics and imaging.
   We continue to establish and optimize assays and strategies for genetic and imaging studies. We have, for instance, developed approaches for: germline knock-ins of fluorophores; a genetic biosynthetic pathway screen for non-template-derived compounds (lipids and sugars); a scaled-intensity RNAi approach for the analysis of maternal-effect early lethal genes with pleiotropic functions.

Research Team

Verena Gobel, MD
Principle Investigator
Associate Professor, Harvard Medical School and MassGeneral Brigham

Liakot A Khan, PhD
Instructor, Harvard Medical School and Mass General Brigham

Edward Membreno

Publications

Selected Publications

• Jafari G, Khan LA, Zhang H, Membreno E, Yan S, Dempsey G, Göbel V. Branched-chain actin dynamics polarizes vesicle trajectories and partitions apicobasal epithelial membrane domains. Science Advances, Jun 28;9(26). doi: 10.1126/sciadv.ade4022.
• Zhang N, Zhang H, Khan LA, Jafari G, Eun Y, Membreno E, Göbel V. The biosynthetic-secretory pathway, supplemented by recycling routes, determines epithelial membrane polarity. Science Advances 2023; Jun 28; 9(26). doi: 10.1126/sciadv.ade4620.
• Khan LA, Jafari G, Zhang N, Membreno E, Yan S, Zhang H, Göbel V. A tensile trilayered cytoskeletal endotube drives capillary-like lumenogenesis. J Cell Biol. 2019; 2403-2424.
• Zhang H, Abraham N, Khan LA, Göbel V. RNAi-based biosynthetic pathway screens to identify in vivo functions of non-nucleic acid-based metabolites such as lipids. Nature Protocols 2015; 681 - 700.
• Khan LA, Zhang H, Abraham N, Sun L, Fleming JT, Buechner M, Hall DH, Göbel V. Intracellular lumen extension requires ERM-1 dependent apical membrane expansion and AQP-8 mediated flux. Nat Cell Biol 2013; 143 - 156.
• Zhang H, Kim A, Abraham N, Khan LA, Hall DH, Fleming JT, Göbel V. Clathrin and AP-1 mediate apicobasal polarity and lumen formation in C. elegans tubulogenesis. Development 2012; 139: 2071-2083.
• Zhang H, Abraham N, Khan LA, Hall DH, Fleming JT, Göbel V. Apicobasal domain identities of expanding tubular membranes depend on glycosphingolipid biosynthesis. Nat Cell Bio 2011; 13(10): 1189 – 1201.
• Barrett PL, Fleming JT, Göbel V. Targeted gene alteration in Caenorhabditis elegans by gene conversion. Nat Genetics 2004; 36: 1231-1237.
• Göbel V, Barrett PL, Hall DH, Fleming JT. Lumen morphogenesis in C. elegans requires the membrane-cytoskeleton linker erm-1. Dev Cell 2004; 6: 865-873.