Pol (HIV)

Pol refers to a gene within the Human Immunodeficiency Virus (HIV) genome. This gene encodes several crucial enzymes essential for HIV replication. These enzymes are produced as a large polyprotein precursor that is subsequently cleaved into its functional components.

The enzymes encoded by the pol gene are:

• Reverse Transcriptase (RT): Converts viral RNA into DNA, allowing the virus to integrate into the host cell's genome. This is a critical step in the HIV lifecycle.
• Protease (PR): Cleaves the polyprotein precursors into individual functional viral proteins, including those produced by pol itself, as well as proteins produced by the gag and env genes. Protease activity is essential for virion maturation and infectivity.
• Integrase (IN): Facilitates the integration of the viral DNA into the host cell's DNA. This integrated viral DNA is called the provirus.
• Ribonuclease H (RNase H): Degrades the RNA strand during reverse transcription.

Due to the essential role of pol-encoded enzymes in HIV replication, they are major targets for antiviral drugs. Reverse transcriptase inhibitors (RTIs) and protease inhibitors (PIs) are commonly used as part of antiretroviral therapy (ART) to suppress viral replication and prevent disease progression. Resistance to these drugs can develop through mutations in the pol gene, which alter the structure of the enzymes and reduce their susceptibility to inhibition. Monitoring pol gene mutations is therefore crucial for guiding treatment decisions and managing drug resistance in HIV-infected individuals.