HIV-1 Tat interacts with LIS1 protein.

Area of Science:

• Molecular Biology
• Cell Biology
• Virology

Background:

• HIV-1 Tat protein activates viral gene transcription via RNA polymerase II (RNAPII) C-terminal domain (CTD) phosphorylation.
• Tat disrupts T-cell metabolism, inhibiting proliferation and inducing apoptosis, partly by distorting microtubule polymerization.
• LIS1 is a microtubule-associated protein crucial for microtubule polymerization.

Purpose of the Study:

• To identify proteins interacting with HIV-1 Tat.
• To investigate the interaction between Tat and LIS1.
• To understand the role of Tat-LIS1 interaction in Tat-induced cellular effects.

Main Methods:

• Biochemical fractionation of T-cell extracts.
• Co-purification assays to identify Tat-associated proteins.
• In vitro binding assays, co-immunoprecipitation, and yeast two-hybrid system to confirm Tat-LIS1 interaction.

Main Results:

• LIS1 was identified as a Tat-interacting protein co-purifying with RNAPII CTD kinase activity.
• Tat directly interacted with LIS1 in vitro and in vivo.
• LIS1 co-immunoprecipitated with Tat in HeLa cells and interacted in a yeast two-hybrid system.

Conclusions:

• HIV-1 Tat protein interacts with LIS1 both in vitro and in vivo.
• This interaction potentially contributes to Tat's effects on microtubule formation and cellular processes.