Kinetoplast DNA (kDNA) (kDNA)

Kinetoplast DNA (kDNA) is a unique and highly organized mitochondrial genome found in kinetoplastid parasites such as Trypanosoma and Leishmania species (Shapiro & Englund, 1999). It consists of a massive network of thousands of interlocked DNA circles, categorized into minicircles and maxicircles, which are essential for the parasite's mitochondrial function and RNA editing processes (Cavalcanti & de Souza, 2018). The high adenine-thymine (AT) content of this DNA makes it a specific target for various diamidines and other minor groove-binding drugs (Dardonville, 2005). These therapeutic agents, such as pentamidine and diminazene, bind to the AT-rich sequences, leading to the inhibition of DNA replication and the induction of dyskinetoplasty, or the total loss of kDNA (Wilson et al., 2008). This disruption is lethal to the parasite, making kDNA a validated target for treating diseases like African sleeping sickness and leishmaniasis. However, the clinical use of kDNA-targeting drugs is often limited by significant side effects, including nephrotoxicity and systemic toxicity, due to their potential to interact with host cellular components at high concentrations (Sands et al., 1985). The complexity of the kDNA network also presents a challenge for drug delivery and the prevention of resistance, as parasites can sometimes survive with altered kDNA structures. Despite these challenges, kDNA remains a cornerstone of anti-protozoal drug research due to its absence in mammalian cells.

Other names

AT-rich kinetoplast DNAMitochondrial DNA of kinetoplastidsMaxicircle DNAMinicircle DNA

Drugs targeting kDNA act as minor groove binders that specifically recognize AT-rich sequences, interfering with mitochondrial Type II topoisomerases and inhibiting DNA replication, which leads to the loss of the kinetoplast (dyskinetoplasty) (Shapiro & Englund, 1999; Wilson et al., 2008).