Brewers’ Yeast Shows the Way

to New Drugs

Two molecular biologists at Zurich University have set up their own company to market

worldwide their innovative screening system for the identification of protein interactions

in cell membranes.

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The DUALmembranesystem detects

interactions betweenintegral membrane

proteins in situ.

CTI Success Story

It was the ancient Egyptians who first used yeast to makebeer, bread and wine. But it wasn’t until centuries later thatLouis Pasteur discovered that these tiny micro-organismsknown to the scientific world as Saccharomyces cerevisiaewere responsible for the process of fermentation. As yeastcells are closely related to human cells, they have been used since the early 19th century as a “laboratory” for bio-chemical experimentation and, more recently, for researchfocusing on genetics and molecular biology.

In Search of New DrugsUsing the yeast two-hybrid system, Professor Stagljar, amolecular biologist at Zurich University, developed an inno-vative process for identifying interactions between proteinsin cell membranes. In 2000, he and a fellow researcher,Professor Michael Hottiger, set up Dualsystems Biotech AGwith support from Professor Ulrich Hübscher at theInstitute of Veterinary Biochemistry and the CTI Start-upInitiative.This novel screening system allows the precursors of newdrugs and disease pathogens to be identified. The advan-tage is that it does not rely on rapid evaluation of sub-stance libraries but takes a specific, targeted approach.There is a good reason why the system is based on pro-teins: now that the human genome has been almost fullydecoded, scientists are able to read some three billiongene building blocks. The human genome probably con-tains the blueprints for between 30,000 and 50,000 pro-teins. Scientists assume that each cell contains up to10,000 different proteins, with each one fulfilling a spe-cific function in a defined location. These proteins arethe real workhorses and tools in our cells. It is vital for theway they work and their “logistics” to be studied sincedisrupted intracellular protein transport, for example, cantrigger incurable diseases.

A Small Test with a Big Impact“If we want to understand the function of a certain proteinin detail, we first need to identify the proteins that inter-act with our target. This is how we reconstruct the puzzleon the protein level”, Igor Stagljar explains. “This showsus whether known or newly identified proteins areinvolved in certain biological processes, and we need thisinformation to elucidate the function of a protein.” Theclever yeast method is the ideal tool for this work.“A large number of human proteins can be produced inthis yeast, where they take on their original structure”,Michael Hottiger explains. “This interchangeability and theunique opportunities for genetic manipulation that yeastcells offer mean that human membrane proteins involvedin diseases can be identified and investigated at themolecular level.”Today, Dualsystems Biotech is the leader in customizedyeast-based screening. The first fruit of the company’sefforts, DUALhybrid technology, is a powerful genetic testfor the functional identification of protein-protein inter-actions in vivo. This is something that is of interest to bothbasic and medical research. Screening technologies design-ed to answer specific questions allow interactions betweenproteins to be identified in practically any environment.The team has also designed a DUALmembrane technologywhich targets integral membrane proteins or membrane-associated proteins which are difficult to characterize usingother methods. DUALmembrane technology allows pro-teins to be analyzed in their natural interactive setting.

These products are aimed at private companies, publicinstitutions and academic research groups who want cus-tomized yeast two-hybrid systems, licences for geneticscreening platforms or to collaborate on protein screeningprojects. There is lively demand for these sophisticatedscreening methods all over the world because of theprospects they offer for identifying ways of treating dis-orders such as tumours, Alzheimer’s disease, arthritis,depression and genetic diseases.

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ContactsDualsystems Biotech AGProf. Dr. Igor Stagljar, Vice-PresidentProf. Dr. Michael Hottiger, Business DevelopmentWinterthurerstrasse 190CH-8057 Zurich

Phone: +41 (0)1 635 54 70E-mail: info@dualsystems.comInternet: www.dualsystems.com

Jeannie CaseyCTI Life SciencesFederal Office for Professional Education and TechnologyEffingerstrasse 27CH-3003 Berne

Phone: +41 (0)31 322 11 07E-mail: jeannie.casey@bbt.admin.chInternet: www.kti-cti.ch

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KTI/CTI | Federal Office for Professional Education and Technology | Effingerstrasse 27 | CH-3003 Berne | www.kti-cti.ch

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