PT  - JOURNAL ARTICLE
AU  - Prescott, Alan R.
AU  - Bales, Alexandra
AU  - James, John
AU  - Trinkle-Mulcahy, Laura
AU  - Sleeman, Judith E.
TI  - Time-resolved quantitative proteomics implicates the core snRNP protein SmB together with SMN in neural trafficking
AID  - 10.1242/jcs.137703
DP  - 2014 Feb 15
TA  - Journal of Cell Science
PG  - 812--827
VI  - 127
IP  - 4
4099  - http://jcs.biologists.org/content/127/4/812.short
4100  - http://jcs.biologists.org/content/127/4/812.full
SO  - J. Cell Sci.2014 Feb 15; 127
AB  - The biogenesis of splicing snRNPs (small nuclear ribonucleoproteins) is a complex process, beginning and ending in the nucleus of the cell but including key stages that take place in the cytoplasm. In particular, the SMN (survival motor neuron) protein complex is required for addition of the core Sm proteins to the snRNP. Insufficiency of SMN results in the inherited neurodegenerative condition, spinal muscular atrophy (SMA). Details of the physical organization of the cytoplasmic stages of snRNP biogenesis are unknown. Here, we use time-resolved quantitative proteomics to identify proteins that associate preferentially with either newly assembled or mature splicing snRNPs. We identified highly mobile SmB protein-trafficking vesicles in neural cells, which are dependent on the cellular levels of SMN and SmB for their morphology and mobility. We propose that these represent a family of related vesicles, some of which play a role in snRNP biogenesis and some that might play more diverse roles in cellular RNA metabolism.