Share this page:
Other services (opens in new window)
Sets a cookie

Ancient protein offers clues to killer condition

Visit  University of Leeds website

12 May 2008

More than 600 million years of evolution has taken two unlikely distant cousins – turkeys and scallops – down very different physical paths from a common ancestor. But University of Leeds researchers have found that a motor protein, myosin 2, remains structurally identical in both creatures.

The discovery suggests that the tiny motor protein is much more important than previously thought – and for humans it may even hold a key to understanding potentially fatal conditions such as aneurisms.

Says Professor Knight of the University’s Faculty of Biological Sciences: "This is an astonishing discovery. Myosin 2’s function is to make the smooth muscle in internal organs tense and relax involuntarily. These creatures have completely different regulatory mechanisms: the myosin in a turkey’s gizzards allows it to ‘chew’ food in the absence of teeth, while that in a scallop enables it to swim. Yet they have exactly the same structure."

Myosin molecules generate tension in smooth muscle by adhering to form a filament, which grabs hold of a neighbouring filament, and relaxes by letting go. When the muscle is in a relaxed state, myosin molecule folds itself up into a compact structure.

This folded structure allows the smooth muscles to adjust to being different lengths so they can operate over a large distance, such as the bladder or the uterus expanding and contracting. In contrast, skeletal muscles operate over a narrow range, defined by how much joints can move.

Professor Knight says: "We were puzzled to find that the scallop’s myosin 2 had retained its ability to fold and unfold, as they don’t need to accommodate a large range of movement. After all, the scallop only moves its shell a little when it swims.

"In evolution, if something is not essential to the survival of an organism, it is not conserved. The fact that the scallop has retained all the functions of its myosin 2 over hundreds of millions of years tells us that this folding is of fundamental functional importance in muscle and that we don’t know as much about it as we need to know."

In humans, any changes in the composition of myosin within the muscles can be fatal. For example, a swelling in the walls of an artery can cause a brain aneurism, while an enlarged heart can lead to cardiac arrest in a young, fit person.

Says Professor Knight: "Because these malfunctions occur in our internal organs, we are often unaware of what is going wrong until it’s too late. Learning how to control myosin, how to move it around without disturbing the delicate balance between filaments and individual molecules, is an emerging area and one we are only just beginning to tackle."

The research, funded by BBSRC, is published in the US journal Proceedings of the National Academy of Sciences (PNAS).

ENDS

Notes to editors

Peter Knight is Professor of Molecular Contractility in the Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds

A copy of the research paper, Conservation of the regulated structure of folded myosin 2 in species separated by at least 600 million years of independent evolution is available on request from the PNAS press office.

About the Faculty of Biological Sciences

The Faculty of Biological Sciences at the University of Leeds is one of the largest in the UK, with over 150 academic staff and over 400 postdoctoral fellows and postgraduate students. The Faculty has been awarded research grants totalling some £60M and funders include charities, research councils, the European Union and industry. Each of the major units in the Faculty has the highest Grade 5 rated research according to the last government (HEFCE) Research Assessment Exercise, denoting research of international standing. The Faculty is also consistently within the top three for funding from the government’s research councils, the BBSRC and NERC. http://www.fbs.leeds.ac.uk

About University of Leeds

The University of Leeds is one of the largest higher education institutions in the UK with more than 30,000 students from 130 countries. With a turnover approaching £450m, Leeds is one of the top ten research universities in the UK, and a member of the Russell Group of research-intensive universities. It was placed 80th in the 2007 Times Higher Education world universities league table. The University's vision is to secure a place among the world's top 50 by 2015. http://www.leeds.ac.uk

About campuspr

campuspr is a public relations company that specialises in promoting university research and knowledge transfer. Working in partnership with the University’s press office, campuspr is contracted by the Faculties of Biological Sciences and Engineering at Leeds to promote the wealth of research projects, grants, new technologies and knowledge transfer activities that these faculties are actively engaged in. For more press releases, see http://www.campuspr.co.uk

About BBSRC

The Biotechnology and Biological Sciences Research Council (BBSRC) is the UK funding agency for research in the life sciences. Sponsored by Government, BBSRC annually invests around £380 million in a wide range of research that makes a significant contribution to the quality of life for UK citizens and supports a number of important industrial stakeholders including the agriculture, food, chemical, healthcare and pharmaceutical sectors. http://www.bbsrc.ac.uk

External contact

Jo Kelly, campuspr Ltd

tel: 0113 258 9880, mob: 07980 267756

Guy Dixon, University of Leeds Press Office

tel: 0113 343 8229

PNAS Press Office

tel: 00 1 202 334 1310

Contact

Matt Goode, Head of External Relations

tel: 01793 413299

Tracey Jewitt, Media Officer

tel: 01793 414694
fax: 01793 413382