SMA with respiratory distress type 1 (SMARD1) and Charcot-Marie-Tooth type 2S (CMT2S) are results of mutations in immunoglobulin mu DNA binding protein 2 ( IGHMBP2 ). IGHMBP2 is a UPF1-like helicase with proposed roles in several cellular processes, including translation. This study examines activator of basal transcription 1 (ABT1), a modifier of SMARD1-nmd disease pathology. Microscale thermophoresis and dynamic light scattering demonstrate that IGHMBP2 and ABT1 proteins directly interact with high affinity. The association of ABT1 with IGHMBP2 significantly increases the ATPase and helicase activity as well as the processivity of IGHMBP2. The IGHMBP2/ABT1 complex interacts with the 47S pre-rRNA 5′ external transcribed spacer and U3 small nucleolar RNA (snoRNA), suggesting that the IGHMBP2/ABT1 complex is important for pre-rRNA processing. Intracerebroventricular injection of scAAV9- Abt1 decreases FVB-
Ighmbp2
nmd/nmd disease pathology, significantly increases lifespan, and substantially decreases neuromuscular junction denervation. To our knowledge, ABT1 is the first disease-modifying gene identified for SMARD1. We provide a mechanism proposing that ABT1 decreases disease pathology in FVB-
Ighmbp2
nmd/nmd mutants by optimizing IGHMBP2 biochemical activity (ATPase and helicase activity). Our studies provide insight into SMARD1 pathogenesis, suggesting that ABT1 modifies IGHMBP2 activity as a means to regulate pre-rRNA processing.
The ATP-binding cassette (ABC) transporter superfamily, one of the largest membrane protein families, plays a crucial role in multidrug resistance (MDR) in cancer by mediating the efflux of various chemotherapeutic agents, thereby lowering their intracellular concentrations and diminishing therapeutic effectiveness. Beyond drug efflux, these transporters are also involved in vital biological processes, such as signal transduction in cancer. Over the past few decades, extensive structural and functional research has provided valuable insights into ABC transporters’ broad substrate specificity and transport mechanisms, leading to promising strategies for overcoming MDR. This review will provide a structural understanding of the interactions between ABC transporters and inhibitors to develop novel cancer therapeutics. Additionally, we focus on methods such as irradiation-based immune therapies, thermal therapies, nanomedicine, CRISPR-Cas, and natural therapies that can genetically modify ABC transporters to reduce their expression or reverse the drug efflux ability. Knowledge gained from these approaches can then be translated into the development of new cancer therapeutics that can combat chemotherapy resistance.
Protein tyrosine kinases (PTKs) are key enzymes of cellular signaling, regulating key processes such as proliferation, differentiation, migration, metabolism, and apoptosis. TKs modulate protein functions in normal and disease states by phosphorylation of tyrosine residues on target proteins. On this critical role, dysregulation of TKs is directly linked with disease progression, particularly in cancer, therefore making TKs an attractive target for therapeutic intervention. The PTK family is broadly classified into receptor tyrosine kinases (RTKs) and non-receptor tyrosine kinases (NRTKs), having variation at both structural and functional levels. RTKs are membrane-bound kinases that initiate intracellular signaling when they react with extracellular ligands, whereas NRTKs within the cytoplasm or nucleus convey intracellular signaling upon receptor activation. This review aims at the organization, mechanistic activity, and therapeutic potential of PTKs, with a particular focus on epidermal growth factor receptor (EGFR) and Src kinase as representative of RTK and NRTK, respectively. Additionally, this review also focuses on addressing emerging strategies to enhance TKI efficacy and overcome acquired resistance in cancer therapy.
The ATP-binding cassette (ABC) transporter superfamily, one of the largest membrane protein families, plays a crucial role in multidrug resistance (MDR) in cancer by mediating the efflux of various chemotherapeutic agents, thereby lowering their intracellular concentrations and diminishing therapeutic effectiveness. Beyond drug efflux, these transporters are also involved in vital biological processes, such as signal transduction in cancer. Over the past few decades, extensive structural and functional research has provided valuable insights into the broad substrate specificity and transport mechanisms of ABC transporters, leading to promising strategies for overcoming MDR. This review will provide a structural understanding of the interactions between ABC transporters and inhibitors to develop novel cancer therapeutics. Additionally, we focus on methods such as irradiation-based immune therapies, thermal therapies, nanomedicine, CRISPR-CAS, and natural therapies that can genetically modify ABC transporters to reduce their expression or reverse the drug efflux ability. Knowledge gained from these approaches can then be translated into the development of new cancer therapeutics that can combat chemotherapy resistance.