Proper three-dimensional structure of proteins is paramount to their function, and misfolded proteins not only lead to loss of that function but to aggregates that can disrupt cellular processes. In ideal conditions, proteins fold spontaneously into their native three-dimensional structures, driven by their amino acid sequence (Ellis, 1999). However, in the crowded and stressed environment of the cell, assistance is often required to avoid misfolding and aggregation. This week we highlight heat shock protein 60 (HSP60), pictured here in the mitochondria of U2OS cells. As a member of the class 1 chaperonin family, HSP60 assists in the folding of newly translated, imported, or denatured proteins in the mitochondrial matrix, particularly under conditions of stress such as high temperatures or UV light ( Hartl, 1996)...Read more

The defense mechanism of our adaptive immune system relies on the antigen-recognition abilities of two molecules: T cell receptors (TCRs), attached to the surface of T cells, and immunoglobins (Igs), anchored to and secreted by B cells. These molecules are equipped with pockets that bind with remarkable selectivity to a specific antigen. Our bodies maintain an estimated 1014 specificities for Igs and a whopping 1018 for TCRs. Considering our entire genome harbors approximately 105 genes, how is this diversity achieved?..Read more

Tight junctions are cell-cell contacts formed at the apical-most part of the lateral membrane between polarized cells and are important players in maintaining the homeostasis and the integrity of epithelia and endothelia. Claudin-3 is one of the central components in tight junction complexes...Read more

In this image of the month we focus on the microtubules and the protein CAMSAP2. Microtubules are filaments that, together with the other components of the cytoskeleton, provide structure and shape to our cells. They also play important roles in intracellular transport, cell division, as well as the formation of cilia and flagella. Microtubules are formed by the polymerization and lateral association of alpha - and beta-tubulin proteins into a hollow tubelike filament. Due to the end-to-end linear arrangement of the α- and β-tubulin dimers the filaments have a polarity, which is crucial for their dynamics and their biological functions ( Akhmanova and Steinmetz, 2015)...Read more

Enolase 1 (ENO1), or alpha enolase, is a glycolytic enzyme with a highly interesting subcellular localization profile. In the subcellular section of the Human Protein Atlas, it is apparent that alpha enolase can be found both in the cytosol, at the plasma membrane and in the nucleus, making it one of thousands of multi-localizing proteins...Read more