Genome-wide RNAi screening identifies human proteins with a regulatory function in the early secretory pathway

Area of Science:

• Cell Biology
• Molecular Biology

Background:

• The secretory pathway is crucial for transporting molecules within mammalian cells.
• Understanding its regulation is key to cellular function.

Purpose of the Study:

• To identify proteins that regulate the mammalian secretory pathway.
• To explore the connections between secretory pathway function and other cellular processes.

Main Methods:

• Automated microscopy-based genome-wide RNA interference screens in human cells.
• Protein cloning, fluorescent tagging, and subcellular localization analysis.
• Analysis of COPII and COPI vesicular coat complexes and Golgi morphology.
• Network analysis to identify functional links.

Main Results:

• Identified 554 proteins influencing secretion.
• Over two-thirds of analyzed proteins localized to the secretory or endocytic pathways.
• Depletion of 143 proteins perturbed early secretory pathway components (COPII, COPI) or Golgi morphology.
• Discovered links between the secretory pathway, GTP-binding proteins, actin cytoskeleton, and EGF receptor signaling.

Conclusions:

• This research provides a comprehensive resource for studying mammalian cell secretion.
• It highlights novel regulatory networks impacting the secretory pathway and cellular organization.