Mapping the MOB proteins' proximity network reveals a unique interaction between human MOB3C and the RNase P complex

Area of Science:

• Cell Biology
• Molecular Biology
• Protein Interactions

Background:

• The functions of most monopolar spindle-one-binder (MOB) proteins are unknown, except for MOB1's role in the Hippo pathway.
• Understanding MOB protein interactions is key to defining their biological roles, as they act as adaptors.

Purpose of the Study:

• To define the protein interactomes of all seven human MOB proteins.
• To identify novel MOB protein interactions and functions, particularly for less-studied MOB family members.

Main Methods:

• Proximity-dependent biotin identification (BioID) was used to map protein-protein interactions for all human MOB proteins.
• Interaction data was analyzed to identify common and differential interactors across MOB subfamilies and individual proteins.
• Specific interactions were validated using affinity purification-mass spectrometry and biochemical assays.

Main Results:

• Over 200 protein interactions were identified for human MOB proteins, with at least 70% being previously unreported.
• The study confirmed known interactions for well-characterized MOB proteins.
• A novel interaction was discovered between MOB3C and subunits of the RNase P complex, essential for tRNA maturation.

Conclusions:

• This study provides a comprehensive interactome map for human MOB proteins, revealing novel biological functions.
• The findings establish a link between MOB proteins, specifically MOB3C, and RNA biology through the RNase P complex.
• The data offers new insights into the diverse roles of the MOB protein family beyond the Hippo pathway.