Additional tyrosine kinases

The term "Additional tyrosine kinases" is a non-specific, collective designation used to describe a variety of enzymes that catalyze the phosphorylation of tyrosine residues on protein substrates (UniProt Consortium, 2024). This group encompasses both receptor tyrosine kinases (RTKs), which span the cell membrane to relay extracellular signals, and non-receptor tyrosine kinases (nRTKs), which operate within the cytoplasm (Lemmon & Schlessinger, 2010). These proteins are fundamental components of signal transduction pathways that govern cell growth, proliferation, and survival (Paul & Mukhopadhyay, 2004). In many malignancies, these kinases are subject to genetic alterations, such as mutations or amplifications, leading to aberrant signaling that drives oncogenesis (Jiao et al., 2018). Consequently, they are major targets for therapeutic intervention, primarily through the use of small-molecule tyrosine kinase inhibitors (TKIs) (Arora & Scholar, 2005). Because this category is broad, drugs associated with it are often multi-kinase inhibitors that target several distinct enzymes to achieve a broader therapeutic effect or overcome resistance mechanisms (Shah et al., 2004). The designation "Additional" typically implies a subset of kinases that are not the primary focus of a specific study or panel but remain clinically relevant due to their potential for off-target interactions or as secondary drivers of disease.

Other names

Other tyrosine kinasesTyrosine-protein kinasesNon-specific tyrosine kinasesTKs

Tyrosine kinase inhibitors (TKIs) typically function by binding to the ATP-binding pocket of the kinase domain, thereby competitively inhibiting the transfer of a phosphate group to the tyrosine residue of a substrate protein (Arora & Scholar, 2005). This blockade prevents the activation of downstream signaling cascades, such as the MAPK/ERK or PI3K/Akt pathways, which are essential for cell survival and proliferation (Lemmon & Schlessinger, 2010). Some inhibitors may also act through allosteric mechanisms, binding to sites outside the ATP pocket to induce conformational changes that inactivate the enzyme (Jiao et al., 2018).