A few of the projects running in the Almeida-Souza Lab.

The dynamic architecture of the endocytic cytoskeleton

The actin cytoskeleton is present at all endocytic stages. As the plasma membrane invaginates from a flat surface to a highly curved vesicle, the actin cytoskeleton has to co-adapt to these membrane geometries to give way to the budding pit and to provide pushing forces. We want to study what types of transformation the actin cytoskeleton undergoes and to define which proteins regulate each one of these steps.

Techniques: CRISPR/Cas9, Live cell imaging, Super-resolution microscopy.


The interplay between cargo properties and receptor identity in clathrin-mediated endocytosis

The participation of the actin cytoskeleton in clathrin-mediated endocytosis is highly variable. To understand the rules behind it, we will develop a system that will allow us to systematically test side-by-side how cargo characteristics, receptors type and cellular conditions affect actin requirement.

Techniques: Protein biochemistry, CRISPR/Cas9, Microscopy, FACS


The biology of reticular adhesions

Reticular adhesions are a recently discovered type of cellular adhesions. We have discovered that these structures are assembled at a special type of clathrin structures – called flat clathrin lattices – and disassembled in the presence of fibronectin (Hakanpää, JCB 2023). Moreover, we found that the reticular adhesions are disassembled at the start of the process of cell migration. Now, we are curious about many aspects in the biology of these structures: What are the signaling pathways and molecules controlling their assembly and disassembly? What is the role of reticular adhesions in cell migration and cancer? What is their structure and composition in situ.

Techniques: Live cell imaging, biochemistry, CRISPR/Cas9, in vitro reconstitutions.


Method development for the study of protein function and endocytosis

Since the start of the lab, we have developed a very efficient pipeline to generate knock-in cell lines. We are taking advantage of this expertise to develop/improve on methods to study endocytosis and protein function. For example, we have a proof-of-concept for a method that allow us to precisely measure the internalization and recycling of any transmembrane protein. We now aim to expand and improve on this technology for clinical applications and curiosity-driven research. We are also developing a degron system with zero basal degradation to study protein function.

Techniques: CRISPR/Cas9, Live cell imaging, protein biochemistry.


FCHSD2 function in health and disease

The F-BAR protein FCHSD2 is a major activator of actin polymerisation in clathrin-mediated endocytosis. Importantly, this protein has been linked to a few diseases. Using our knowledge on the FCHSD2 biology we have developed an assay to screen for compounds capable to disrupt its function. A compound with such activity will allow us to further understand FCHSD2 function in health and disease.

Techniques: Protein biochemistry, Drug screening, Cellular assays, Crystallography