Breaking the code for nuclear domains: the case of b-bodies
Disciplines
Integrative Biology | Structural Biology
Abstract (300 words maximum)
The eukaryotic nucleus is a busy place with a high concentration of proteins performing diverse functions. Despite the crowded environment and absence of internal membranes, nuclear organization remains structured via distinct areas that selectively recruit and release proteins – nuclear domains. How nuclear domains are formed and maintained is currently not well understood.
B-bodies are a newly discovered type of nuclear domains that can be found in the indirect flight muscles of Drosophila; their principle resident is the RNA-binding protein Bruno. This protein has 3 RNA-recognizing motifs (RRM1,2,3) as well as two disordered regions. B-bodies are highly dynamic domains which appearance changes during myogenesis. We used ectopic expression of GFP-tagged Bruno mutants to identify critical regions in the primary sequence that are required for B-body targeting.
Our results indicate that a functional RRM2 domain is required for Bruno trafficking to B-bodies. In contrast, the functionality of RRM3 domain is dispensable in this regard. We speculate that RRM2 domain may be necessary to interact with yet unknown structural RNA molecule(s) in order to retain Bruno in B-bodies.
Academic department under which the project should be listed
CSM - Molecular and Cellular Biology
Primary Investigator (PI) Name
Anton Bryantsev
Breaking the code for nuclear domains: the case of b-bodies
The eukaryotic nucleus is a busy place with a high concentration of proteins performing diverse functions. Despite the crowded environment and absence of internal membranes, nuclear organization remains structured via distinct areas that selectively recruit and release proteins – nuclear domains. How nuclear domains are formed and maintained is currently not well understood.
B-bodies are a newly discovered type of nuclear domains that can be found in the indirect flight muscles of Drosophila; their principle resident is the RNA-binding protein Bruno. This protein has 3 RNA-recognizing motifs (RRM1,2,3) as well as two disordered regions. B-bodies are highly dynamic domains which appearance changes during myogenesis. We used ectopic expression of GFP-tagged Bruno mutants to identify critical regions in the primary sequence that are required for B-body targeting.
Our results indicate that a functional RRM2 domain is required for Bruno trafficking to B-bodies. In contrast, the functionality of RRM3 domain is dispensable in this regard. We speculate that RRM2 domain may be necessary to interact with yet unknown structural RNA molecule(s) in order to retain Bruno in B-bodies.