Normal human cell proteins that interact with the adenovirus type 5 E1B 55kDa protein

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• The human adenovirus type 5 (HAdV-C5) E1B 55kDa protein plays crucial roles in viral infection, partly through a viral E3 ubiquitin ligase complex.
• However, key substrates of this ligase and functions independent of it remain largely unknown.

Purpose of the Study:

• To identify proteins specifically associated with the HAdV-C5 E1B 55kDa protein.
• To characterize the cellular interactome of the E1B 55kDa protein and understand its role in viral replication and host cell modulation.

Main Methods:

• Immunoaffinity purification of E1B 55kDa-associated proteins from infected human cells.
• Liquid chromatography-mass spectrometry (LC-MS) analysis to identify and quantify bound proteins.
• Infection of cells with wild-type HAdV-C5 and E1B 55kDa protein-null mutant viruses.

Main Results:

• Identification of over 90 E1B 55kDa-associated proteins, including previously known interactors.
• Enrichment of identified proteins in pathways related to the ubiquitin-proteasome system, RNA metabolism, and the cell cycle.
• Demonstration of severe inhibition of viral genome replication upon siRNA and interferon treatment prior to infection.

Conclusions:

• The E1B 55kDa protein interacts with a broad range of cellular proteins involved in fundamental cellular processes.
• These findings provide a comprehensive protein interaction map for the E1B 55kDa protein, aiding in understanding its multifaceted roles during HAdV-C5 infection.
• The study highlights the importance of host-pathogen interactions and potential therapeutic targets in adenovirus infections.