Retrovirus Life Cycles

A retrovirus is a single-stranded RNA virus that binds to specific cell surface receptors on a targeted host cell's outer membrane, fuses, and enters via endocytosis to replicate its genetic material in a unique way.

After enter the host's cell, the capsid is uncoated and the enzyme reverse transcriptase or RT binds to the viral RNA, synthesizing complementary DNA and with time, double-stranded DNA the reverse of the usual pattern.

Inside the nucleus of the host cell, the viral DNA is integrated into the host DNA forming a provirus. Thus the viral DNA is actively transcribed whenever the host DNA is transcribed, forming messenger RNA.

This mRNA exits the nucleus, enters the cytoplasm, and is translated to form new viral proteins, which can then assemble into new retroviruses that butt out of the cell and are ready to infect other cells.