RBPMS, short for “RNA-binding protein with multiple splicing,” is a protein. This protein is a member of the RNA recognition motif (RRM) family, known for binding to RNA molecules. Its designation highlights its involvement in processing RNA transcripts, a central activity in the flow of genetic information. RBPMS helps dictate how genetic blueprints are translated into functional components of the cell.
How RBPMS Works
RBPMS functions primarily as an RNA-binding protein (RBP), regulating gene expression. It interacts directly with various RNA molecules, particularly messenger RNA (mRNA) precursors, to process them. One of its main activities is in alternative splicing, a process where different protein versions can be produced from a single gene by selecting which segments of the mRNA are included or excluded. RBPMS can either activate or repress these splicing events, controlling specific pre-mRNA targets.
This protein binds to specific sequences within RNA, often involving tandem CAC trinucleotide motifs. The minimal RNA length required for RBPMS binding to these motifs is approximately 15 nucleotides, with variable spacing between 1 and 9 nucleotides. Beyond splicing, RBPMS also affects mRNA stability and translation, the synthesis of proteins from mRNA. By coordinating these post-transcriptional events, RBPMS ensures that the correct proteins are produced in the right amounts, maintaining cellular function.
RBPMS in Vision and Nerves
RBPMS plays a role in specialized tissues, particularly the retina and the nervous system. In the mammalian retina, RBPMS is found predominantly in retinal ganglion cells (RGCs), which are neurons responsible for transmitting visual information from the eye to the brain. Its expression in RGCs makes it a specific marker for these cells. RBPMS is found in the cell bodies and primary dendrites of these RGCs, with weaker presence in thinner dendrites and axons near the optic nerve head.
RBPMS is involved in the development, function, and maintenance of RGCs. While RBPMS immunostaining is largely absent in other retinal cells like photoreceptors, bipolar cells, and amacrine cells, its concentrated expression in RGCs highlights its importance in visual processing. Beyond the retina, RBPMS is also expressed in other neural tissues and has a broader impact on neurological health. Its involvement in RNA processing is important for the proper development and function of neurons, influencing processes like synaptic plasticity, fundamental for learning and memory.
RBPMS and Health Conditions
Dysfunction of RBPMS, due to genetic mutations or altered regulation, can lead to various health conditions. In the eye, RBPMS is directly linked to inherited retinal diseases, disorders characterized by progressive vision loss. Mutations in the RBPMS gene have been identified as a cause of certain forms of retinitis pigmentosa (RP). RP is a genetic disorder causing gradual deterioration of light-sensing cells in the retina, leading to progressive vision loss, including “tunnel vision”.
When RBPMS does not function correctly in the retina, it can disrupt the precise molecular processes necessary for maintaining healthy retinal ganglion cells, contributing to their degeneration. Beyond ocular conditions, the role of RNA-binding proteins like RBPMS in regulating gene expression also implicates them in various neurological disorders. While specific neurological conditions directly caused by RBPMS malfunction are still being investigated, the general disruption of RNA homeostasis by dysfunctional RNA-binding proteins can contribute to neurodegeneration.