ADP-ribosylation of proteins was first described in the early 1960's, and today the function and regulation of poly(ADP-ribosyl)ation (PARylation) is partially understood. By contrast, little is known about intracellular mono(ADP-ribosyl)ation (MARylation) by ADP-ribosyl transferase (ART) enzymes, such as ARTD10. Recent findings indicate that MARylation regulates signalling and transcription by modifying key components in these processes. Emerging evidence also suggests that specific macrodomain-containing proteins, including ARTD8, macroD1, macroD2 and C6orf130, which are distinct from those affecting PARylation, interact with MARylation on target proteins to 'read' and 'erase' this modification. Thus, studying macrodomain-containing proteins is key to understanding the function and regulation of MARylation.

Integrins mediate cell-matrix and cell-cell interactions and integrate extracellular cues to the cytoskeleton and cellular signalling pathways. Integrin function on the cell surface is regulated by their activity switching such that intracellular proteins interacting with the integrin cytoplasmic domains increase or decrease integrin-ligand binding affinity. It is widely accepted that integrin activation by specific proteins is essential for cell adhesion and integrin linkage to the actin cytoskeleton. However, there is also increasing evidence that integrin-inactivating proteins are crucial for appropriate integrin function in vitro and in vivo and that the regulation of integrin-ligand interactions is a fine-tuned balancing act between inactivation and activation.

The cloning of the founding member of the Hedgehog (HH) family of secreted proteins two decades ago inaugurated a field that has diversified to encompass embryonic development, stem cell biology and tissue homeostasis. Interest in HH signalling increased when the pathway was implicated in several cancers and congenital syndromes. The mechanism of HH signalling is complex and remains incompletely understood. Nevertheless, studies have revealed novel biological insights into this system, including the function of HH lipidation in the secretion and transport of this ligand and details of the signal transduction pathway, which involves Patched 1, Smoothened and GLI proteins (Cubitus interruptus in Drosophila melanogaster), as well as, in vertebrates, primary cilia.