Question

We’ve seen in this lab exercise that proteins can be involved in more than one biological process or KEGG pathway. Based on what you’ve learned in Cell Biology Lecture or Lab, describe a protein that has a role in multiple processes or pathways. Include in your answer the name of the protein and in which pathway or process it is involved.

Answer 1

TBK1 or TANK binding kinase is a protein that has a role in multiple processes or pathways.

Kinases function to chemically modifies other proteins by adding a phosphate group (from ATP) to them. This is known as phosphorylation, a process that regulates the biological activity of proteins. TBK1 is a serine/threonine-protein kinase that plays multiple roles in cell proliferation, autophagy, apoptosis as well as anti-tumor immunity. It is involved in many signaling pathways and forms a node between them. Due to its involvement in many pathways, mutation or deregulation in its activity leads to many neurodegenerative and auto-immune diseases.

TBK plays an important role in the regulation of interferon (IFN)-inducible genes during the immune responses to bacterial and viral infections. It phosphorylates IRF3, a transcription factor that is translocated to the nucleus to promote the production of type-1 interferons. TBK1 also phosphorylates signal transducer and activator of transcription 6 to further aid signal transduction and gene expression.

It is also known for its role in autophagy involved in pathogenic clearance by phosphorylating ubiquitin-bindin protein p62. TBK1 suppresses expression of certain interferon-responsive genes in dendritic cells, to regulate immune tolerance and also suppress autoimmunity.