Gap Junctions
Understanding Gap Junction Composition and Functional Diversity
We explore the compositional diversity of gap junctions, focusing on the 21 human connexin (Cx) isoforms and their ability to mix and match within and across tissues. By studying how different isoforms contribute unique properties to gap junction intercellular communication (GJIC), we aim to elucidate the molecular mechanisms that drive ionic and small molecule exchange. This research seeks to uncover how Cx diversity impacts tissue physiology and how mutations or misregulation of Cx proteins contribute to diseases such as deafness, epilepsy, neurodegeneration, and cancer.
(A) Schematic representation of the FETCH (Flow Enabled Tracking of Connexosomes in HEK cells). Separate populations of cells transfected with either GFP or RFP tagged Cxs are coplated and allowed to interact to for dual-labeled connexosomes. The presence of dual-labeled connexomes is observable as a robust flow cytometry phenotype (inset). and (B) Dual-labeled connexomes are observable in post-sorting samples of FETCH experiments via confocal microscopy. (C) Heat map representation of combinatorial heterotypic analysis of several Cx isoforms demonstrating scalability of the FETCH method to evaluate interactions between several human Cx isoforms.
Deciphering Gap Junction Regulation via Plaques and Connexosomes
Our lab investigates the dynamic regulation of gap junctions, particularly the roles of plaques (large clusters of gap junction channels) and connexosomes (specialized vesicles mediating the turnover of fully-docked gap junction channels). We aim to understand how these structures regulate channel assembly, disassembly, and recycling, as well as their influence on GJIC in health and disease. By characterizing the mechanisms governing these processes, we hope to provide new insights into the maintenance and modulation of intercellular communication.
Figure: Two HEK 293FT cells expressing fluorescently-tagged Cx constructs. One construct is Cx-miRFP670 and the other is Cx-mEmerald-T2A-RFP. Coplating these two cell populations allows us to clearly observe plaque and connexosome formation and dynamics.
Engineering Connexin-Based Tools to Reprogram Intercellular Communication
We develop innovative tools to manipulate gap junction function, using protein engineering and high-throughput screening to design novel Cx-based systems. These tools aim to selectively rewrite or control intercellular communication in disease contexts, enabling targeted approaches to address conditions linked to impaired gap junction function. By combining cutting-edge technologies such as flow cytometry-based interaction assays and super-resolution imaging, we are advancing new strategies for therapeutic intervention.