Messenger RNA Localization In Yeast Yields New Clues On Development

July 18, 1997

The development of a complex organism from a single cell requires the establishment of daughter cells with different gene expression programs. it has been known for some time that such differential gene expression in the earliest-stage embryos of complex creatures such as drosophila is mediated, at least in part, by the localization of messenger RNA (mRNA) coding for gene-control proteins. Now new research from the laboratory of Robert Singer at the Albert Einstein College of Medicine, published in the July 18 issue of Science, indicates that mRNA localization also can regulate differential gene expression in Saccharomyces cerevisiae, commonly know as Brewer's yeast. The existence of the phenomenon in a eukaryotic cell type as evolutionarily ancient as yeast implies that mRNA localization may be a fundamental mechanism of different gene regulation for development and other processes.

The paper, whose first author is postdoctoral fellow Roy Long, is published in the July 18 issue of Science. Long and his colleagues studied a yeast protein called ASH1. This protein plays a critical role in distinguishing "daughter" yeast cells from the mother cells from which they bud. This distinction between the two cells is fundamental: A mother cell can change its "mating type" while the daughter cell cannot. Members of the laboratory of Dr. Kim Nasmyth of the Austrian Research Institute of Molecule pathology, a co-author of the Science paper, had previously tracked this difference down to a negative gene control protein called ASH1, which the daughter cell possesses at a substantially higher level than the other cell does.

In the new paper, Long and colleagues report that the differential gene expression controlled by ASH1 is due to the localization of ASH1 mRNA, which is directed to the tip of the budding daughter cell. Long and his colleagues also report that the message's movement depends on components of the actin cytoskeleton, and that a myosin mother is involved in the transport. They also identified a special "zipcode" region on the messenger RNA that directs it to the proper place in the cell.

For the past decade, Singer and his colleagues have conducted pioneering research demonstrating that mRNA localization is an important mechanism by which the cells of higher organisms regulate cell structure and function. But the discovery of mRNA localization in yeast shows that the process was presented early in evolution and thus is a fundamental one. In fact, it may have played an important role in the regulation of development as higher, multicellular organisms evolved. The localization of mRNA in yeast may even give support to the notion that the earliest biotic world was an "RNA world"--one in which RNA, not DNA, performed all the cell's vital information-storage and regulatory roles, including the control of the expression of genetic instructions.

Moreover, when fundamental cellular mechanisms go awry, disease can often result. Indeed, the Singer group has already found that myotonic dystrophy, the most common form of adult muscular dystrophy, probably occurs because of a defect in RNA localization. Neurological diseases such as Alzheimer's Disease and schizophrenia have also been traced to the faulty migration of developing nerve cells, and these and other diseases may be due, at least in part, to the faulty localization of mRNAs responsible for neuronal movement.
-end-


Albert Einstein College of Medicine

Related RNA Articles from Brightsurf:

A new RNA catalyst from the lab
On the track of evolution: a catalytically active RNA molecule that specifically attaches methyl groups to other RNAs - a research group from the University of Würzburg reports on this new discovery in Nature.

Small RNA as a central player in infections
The most important pathogenicity factors of the gastric pathogen Helicobacter pylori are centrally regulated by a small RNA molecule, NikS.

RNA as a future cure for hereditary diseases
ETH Zurich scientists have developed an RNA molecule that can be used in bone marrow cells to correct genetic errors that affect protein production.

Bringing RNA into genomics
By studying RNA-binding proteins, a research consortium known as ENCODE (Encyclopedia of DNA Elements) has identified genomic sites that appear to code for RNA molecules that influence gene expression.

RNA key in helping stem cells know what to become
If every cell has the same genetic blueprint, why does an eye cell look and act so differently than a brain cell or skin cell?

RNA structures by the thousands
Researchers from Bochum and Münster have developed a new method to determine the structures of all RNA molecules in a bacterial cell at once.

New kind of CRISPR technology to target RNA, including RNA viruses like coronavirus
Researchers in the lab of Neville Sanjana, PhD, at the New York Genome Center and New York University have developed a new kind of CRISPR screen technology to target RNA.

Discovery of entirely new class of RNA caps in bacteria
The group of Dr. Hana Cahová of the Institute of Organic Chemistry and Biochemistry of the CAS, in collaboration with scientists from the Institute of Microbiology of the CAS, has discovered an entirely new class of dinucleoside polyphosphate 5'RNA caps in bacteria and described the function of alarmones and their mechanism of function.

New RNA mapping technique shows how RNA interacts with chromatin in the genome
A group led by scientists from the RIKEN Center for Integrative Medical Sciences (IMS) in Japan have developed a new method, RADICL-seq, which allows scientists to better understand how RNA interacts with the genome through chromatin--the structure in which the genome is organized.

Characterising RNA alterations in cancer
The largest and most comprehensive catalogue of cancer-specific RNA alterations reveals new insights into the cancer genome.

Read More: RNA News and RNA 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.