nucleoside transport

Definition

Target type: biologicalprocess

The directed movement of a nucleoside, a nucleobase linked to either beta-D-ribofuranose (ribonucleoside) or 2-deoxy-beta-D-ribofuranose, (a deoxyribonucleotide), into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore. [GOC:ai]

Nucleoside transport is a fundamental biological process essential for the uptake and delivery of nucleosides, the building blocks of DNA and RNA, into cells. It involves the movement of these molecules across cell membranes, a process crucial for various cellular functions, including DNA replication, RNA transcription, and protein synthesis.

The process of nucleoside transport is mediated by specific membrane proteins called nucleoside transporters. These proteins are highly selective, recognizing and transporting particular nucleosides or nucleoside analogs. There are two primary types of nucleoside transporters:

**1. Equilibrative nucleoside transporters (ENTs):** These transporters facilitate the bidirectional movement of nucleosides across the cell membrane, driven by the concentration gradient of the nucleoside. ENTs play a vital role in maintaining nucleoside homeostasis within cells.

**2. Concentrative nucleoside transporters (CNTs):** These transporters actively transport nucleosides against their concentration gradient, utilizing energy from ATP hydrolysis. CNTs are responsible for the efficient uptake of nucleosides into cells, particularly in tissues with high metabolic demands, such as the liver and intestines.

The process of nucleoside transport begins with the binding of a nucleoside to the transporter protein. This binding triggers a conformational change in the protein, allowing the nucleoside to move across the cell membrane. Once inside the cell, the nucleoside can be utilized for various metabolic processes, such as the synthesis of nucleotides, DNA, and RNA.

The specificity of nucleoside transporters for different nucleosides is determined by the structure of the transporter protein. This specificity is crucial for maintaining cellular homeostasis and ensuring the proper functioning of various metabolic pathways.

Disruptions in nucleoside transport can have significant consequences for cell function and health. Defects in nucleoside transporters can lead to various genetic diseases, including severe combined immunodeficiency (SCID) and Lesch-Nyhan syndrome. Furthermore, nucleoside analogs are often used as chemotherapeutic agents for the treatment of cancer, exploiting the mechanisms of nucleoside transport to target cancer cells.

In conclusion, nucleoside transport is a critical biological process that ensures the availability of essential building blocks for DNA and RNA synthesis. The process is mediated by specific transporter proteins that exhibit high selectivity for different nucleosides. Understanding the intricacies of nucleoside transport is vital for developing new therapeutic strategies for various diseases and for gaining insights into the fundamental mechanisms of cell function.'
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Proteins (2)

Compounds (19)