A previously unknown cellular component: a new cellular component that is important for the sense of smell

Researchers at Umeå University in Sweden have discovered a previously unknown cellular component, an organelle
, in the neurons we use to sense odors.
This finding may have implications for further research into impaired smell, a common symptom
of COVID-19.

Staffan Bohm, a professor in the Department of Molecular Biology, said: "The prerequisite for finding a cure for olfactory impairment is to first understand how smell works
.
"

What the researchers found was a special organelle that resides inside nerve cells that had not been observed
before.
The newly discovered organelle is named Multivesicular Transducosome
.
This discovery was made possible by the unique microscope infrastructure
of Umeå University.

Organelles are different "workstations" within cells that can be compared to different organs of the body, that is, different organelles have different functions
in the cell.
Most organelles are common in different types of cells, but there are also some organelles that have specific functions and only appear in certain types of
cells.
Olfactory nerve cells have long protrusions, i.
e.
cilia, that reach into the nasal cavity and contain proteins that bind odorous substances, thus initiating nerve impulses to the brain
.
The conversion of odors into nerve impulses is called transduction, while the newly discovered organelles contain only transducer proteins
.

The role of transducers is to store and hold transduced proteins separated from each other until they are needed
.
Under olfactory stimulation, the outer membrane of organelles ruptures, releasing conduction proteins that allow them to reach the cilia of neurons and smell is perceived
.

The researchers also found that the transducer carries a protein called retinitis pigmentosa 2 (RP2), which regulates transduction
in the eye's photoreceptor cells.
If the RP2 gene is mutated, it can lead to mutations in retinitis pigmentosa in the eye disease, damaging the photosensitive cells
of the eye.

"One question that needs further study is whether this transducer plays a role in vision and whether it exists in
brain neurons activated by neurotransmitters rather than light and smell.
" If so, this finding could be even more significant," Bohm said
.

The transducer was discovered
when researcher Devendra Kumar Maurya used a new technique called correlation microscopy.
This technique combines electron microscopy and confocal microscopy, so it is possible to simultaneously image the internal structure of the cell and the location of
different proteins.
Crucial to this discovery is this method, which enables the technique to be used to analyze intact neurons
in tissue sections.