Decades old debate settled: Golgi key to maintenance of molecule-sorting station in cells

December 02, 2019

On a daily basis, multitudes of molecules enter each cell in our body. These can be nutrients or signal molecules or pathogenic microorganisms. An organelle in the cell directs these molecules to other stations for further processing. This organelle is called the endosome. If the pathways by which this sorting occurs fails at any stage, several diseases such as neurodegenerative diseases and certain cancers can occur. Thus, a better understanding of the steps in these pathways is of utmost importance.

In a recent study published in Communications Biology, a group of scientists from Japan and Austria, led by Prof Jiro Toshima from the Tokyo University of Science, reports a new finding regarding the maintenance and functioning of the endosome.

Conventional knowledge is that two processes are necessary for the upkeep of endosomes: a) sacs of molecules constantly form at the cell membrane, are transported to the endosome, and fuse into it; b) protein-containing vesicles transported from the Golgi (another cell organelle) fuse with the endosome.

The researchers of this study claim that this is not the case.

They introduce genetic mutations and drugs into yeast cells to inhibit each of these transport processes at a time. When transport from the Golgi does not occur, a protein essential to the upkeep of the endosome, Rab5, is not activated, and endosome formation is affected. When cell transport from the membrane is inhibited, there is no effect on the endosome. Thus, essentially, transport from the Golgi is necessary and that from the cell membrane is dispensable, or not as crucial. "Our results provide a different view of endosome formation and identify the Golgi as critical for the optimal maintenance and functioning of endosomes," Prof Toshima says. This study clarifies only a fraction of the molecule-sorting pathway in cells. But, this is certainly one giant step in the research in this field. Perhaps, the insights from this study will soon appear on the pages of cell biology textbooks.
-end-
About the Tokyo University of Science

Tokyo University of Science (TUS) is a well-known and respected university, and the largest science-specialized private research university in Japan, with four campuses in central Tokyo and its suburbs and in Hokkaido. Established in 1881, the university has continually contributed to Japan's development in science through inculcating the love for science in researchers, technicians, and educators.

With a mission of "Creating science and technology for the harmonious development of nature, human beings, and society", TUS has undertaken a wide range of research from basic to applied science. TUS has embraced a multidisciplinary approach to research and undertaken intensive study in some of today's most vital fields. TUS is a meritocracy where the best in science is recognized and nurtured. It is the only private university in Japan that has produced a Nobel Prize winner and the only private university in Asia to produce Nobel Prize winners within the natural sciences field.

Website: https://www.tus.ac.jp/en/mediarelations/

About Professor Jiro Toshima from the Tokyo University of Science

Dr Jiro Toshima is at present a Professor with the Department of Biological Science and Technology at the Tokyo University of Science, Japan. Having begun research in cell biology and related fields in 1999, he has co-authored over 41 publications, and is the lead author of the present paper. From September 2017 to August 2019, he served as a Councillor in the Japanese Biochemical Society.

Funding information

This research was supported by grants to Junko Y. Toshima (JSPS KAKENHI Grant #26440067, the Takeda Science Foundation, the Novartis Foundation, Japan) and to Jiro Toshima (JSPS KAKENHI Grant #19K06571, the Life Science Foundation of Japan, the Uehara Memorial Foundation and the Takeda Science Foundation).

Tokyo University of Science

Related Cell Membrane Articles from Brightsurf:

Lighting the way to selective membrane imaging
A team of scientists at Kanazawa University have shown how water-soluble tetraphenylethene molecules can become fluorescent when aggregating at a biomembrane-mimetic liquid-liquid interface.

What membrane can do in dealing with radiation
USTC recently found that polymethylmethacrylate (PMMA) and polyvinyl chloride (PVC) can release acidic substance under γ radiation, whose amount is proportional to the radiation intensity.

Bioelectronic device achieves unprecedented control of cell membrane voltage
Every living cell maintains a voltage across the cell membrane that results from differences in the concentrations of charged ions inside and outside the cell.

Novel cell membrane model could be key to uncovering new protein properties
Researchers have recently shed light on how cell membrane proteins could be influenced by the lipids around them.

Using light's properties to indirectly see inside a cell membrane
Using properties of light from fluorescent probes is at the heart of a new imaging technique developed at Washington University's McKelvey School of Engineering that allows for an unprecedented look inside cell membranes.

Cell 'membrane on a chip' could speed up screening of drug candidates for COVID-19
Researchers have developed a human cell 'membrane on a chip' that allows continuous monitoring of how drugs and infectious agents interact with our cells, and may soon be used to test potential drug candidates for COVID-19.

Scientists synthesize novel artificial molecules that mimic a cell membrane protein
Scientists at Tokyo Institute of Technology (Tokyo Tech) recently developed an artificial transmembrane ligand-gated channel that can mimic the biological structure and function of its natural counterpart.

Across the cell membrane
Aquaporins and glucose transporters facilitate the movement of substances across biological membranes and are present in all kingdoms of life.

Location, location, location: The cell membrane facilitates RAS protein interactions
Many cancer medications fail to effectively target the most commonly mutated cancer genes in humans, called RAS.

New self-forming membrane to protect our environment
A new class of self-forming membrane has been developed by researchers from Newcastle University, UK.

Read More: Cell Membrane News and Cell Membrane Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.