The Salogiannis Lab uses live-cell microscopy to visualize intracellular dynamics (mRNA, vesicles, organelles, and microtubules). Check out some cool movies below!
Membrane hitchhiking in action.
We discovered a process known as hitchhiking. This video shows a moving peroxisome (magenta) attaching to and moving on a specialized early endosome (green) in the filamentous fungus Aspergillus nidulans. The mechanisms underlying hitchhiking are not clear and is being actively pursued in the Salogiannis lab. Check out our research page for more details! (Movie taken on an OMX Blaze v4 with two-color simultaneous imaging and deconvolution)
Rab8 movement in HeLa cells
The GTPase Rab8 marks post-Golgi vesicles critical for polarized growth. LRRK2 phosphorylates Rab8. We are investigating how LRRK2 regulates Rab8 movement and downstream biology. (Video taken using a CSU-W1 spinning disk confocal)
Rab10 movement in HeLa cells without LRRK2 expression
Rab10 movement in HeLa cells with pathogenic LRRK2 expression
Movie of GFP-Rab10-marked vesicles moving in a HeLa cell. Rab10 is a post-Golgi exocytic carrier critical for polarized secretion and growth. In wild-type cells, the majority of Rab10 puncta move out towards the periphery, in a kinesin-based manner.
In cells expressing LRRK2, Rab10 accumulates near the centrosome at the minus-ends of microtubules and movements become increasingly bidirectional. This is consistent with the recruitment of dynein, which moves towards the minus-end. A goal in the lab is to understand the mechanism underlying this effect.
Early endosome movement in neurons.
Rab5-marked vesicles (early endosomes) exhibiting rapid, bidirectional movement in the axon of a hippocampal neuron. We are interested in understanding how Rab-marked vesicles move in polarized cells (including neurons) and how they influence polarized growth and other biological processes. (Movie captured using a NikonTi TIRF scope).
In vitro motility of kinesin on purified microtubules...
...is blocked by recombinant LRRK2 coated on microtubules
Total internal reflection fluorescence (TIRF) microscopy of single-molecule recombinant kinesins (truncated kinesin-1 or "K560") fused to green fluorescent protein (GFP) moving on purified, taxol-stabilized microtubules. The recombinant species of LRRK2 added is the "RCKW" (C-terminal catalytic half of the protein). (Movies from Deniston*,Salogiannis*, et al., 2020)
Endosome and peroxisome movement in filamentous fungus
Near simultaneous live-cell imaging of early endosomes (green) labeled with GFP-Rab5 (RabA) and peroxisomes (magenta) labeled with mCherry fused to a peroxisome targeting signal sequence. Our lab discovered that a specialized membrane-contact site forms between these two cargos ('hitchhiking') and regulates peroxisome movement (Captured on an OMX Blaze v4 with deconvolution)
Rab6 movement in U-2 OS cells
Movie of GFP-Rab6-marked vesicles moving in a U-2 OS cell. Rab6 is a post-Golgi vesicle critical for exchange with the ER and carrying components for exocytosis.