PINK1 beyond Parkinson’s disease: Towards the structural characterization of the interaction between human PINK1 and Beclin 1

The attention of the scientific community toward PINK1 (PTEN-induced putative kinase 1) has been steadily growing since its discovery as a Parkinson’s disease-causing gene in 2004. This gene encodes a serine/threonine kinase which plays a crucial role in mitochondrial homeostasis, protection from oxidative stress, from neurotoxins, and from the damage caused by intracellular protein aggregates, all pathological mechanisms well known to be involved in neurodegenerative diseases. Research in the last years shed light upon unexpected functions of this protein beyond neuroprotection, in biochemical pathways involved in diabetes, cardiopulmonary disease, inflammation, and, most notably, cancer. Data from previous studies suggest the existence of a direct interaction between PINK1 and Beclin 1. The latter is a member of PI3K complex, a master regulator of autophagy, involved in many pathological processes and already described as a possible target for cancer therapy. The aim of this work is to deepen our knowledge of the structural interaction between PINK1 and Beclin 1. In order to do it, human full-length proteins or parts of them were expressed in bacterial and mammalian cells as tagged or fusion constructs. To face the formation of inclusion bodies, different conditions were tried, including long low-temperature expression followed by extraction of non-classical inclusion bodies with arginine.