Lorne Protein: The protein pioneers

The Lorne Conference on Protein Structure and Function is celebrating its 30th anniversary this year. Graeme O'Neill discovers why there's plenty to celebrate.

Dr Richard Simpson describes the Lorne Conference on Protein Structure and Function, which celebrates its 30th anniversary this month, as "the yardstick by which protein conferences are measured." Simpson, the conference's organiser, attributes its international reputation to Australia's long and rich history of protein research.

Australia established an international presence in protein chemistry long before the word 'proteomics' was coined. It grew out of pioneering research into the chemistry of wool in the 1950s and 1960s by CSIRO's former Division of Protein Chemistry.

"Those people were then recruited by new medical research institutions and became the leading teachers of protein chemistry around the country," Simpson says. "We're very well placed in classical protein chemistry. Looking at where proteomics is today, you now identify proteins with a mass spectrometer. But you still need to apply fundamental techniques of protein fractionation to make MS easier."

Catalyst

Simpson says renowned US protein chemist Ralph Bradshaw was an invited speaker at Lorne several times in the mid-1970s. His experience was the catalyst for him to set up the Protein Society in the US.

"[Lorne Protein] is very highly regarded internationally," Simpson says. "I was in Japan recently at the Pacific Rim International Protein Chemistry Congress, and they want to hold the next Asia-Oceania meeting in Melbourne in 2008 because of the reputation of the Lorne Conference. We're trying to coordinate the activities of protein research societies throughout Asia and Oceania. One of the things we plan to push at the 2006 Lorne conference is the link between proteins and disease."

The associated two-day Lorne Proteomics Symposium grew from the structure-function conference, and has evolved into "a nuts-and-bolts symposium", focused on basic proteomics research, not clinical applications. "We set up the Australasian Proteomics Society to bring the research into a closer relationship with the clinical area -- we no longer get clinicians coming down to the structure-function meeting," Simpson says.

He credits Ludwig colleague Dr Rob Moritz with championing the idea of the Lorne Proteomics Symposium, as a satellite of the structure-function conference. "Proteomics is going to deliver clinical benefits in areas like biomarker discovery, leading to earlier diagnosis of disease," Simpson says.

Change of scene

The 2005 conference (February 6-10) is moving temporarily to Phillip Island, while its traditional venue, Lorne's Erskine on the Beach Hotel, makes major renovations and improvements. One improvement brought by the change of venue is a new lecture hall capable of holding larger audiences -- which Simpson says may influence the size and future direction of the conference.

Eminent St Vincent's Medical Research Institute biochemist Prof Jack Martin will deliver the conference-opening Reece Lecture (see 'Jack Martin's Cheshire cat'). Martin is one of Australia's most cited scientists: last year, the International Scientific Index named him Australian Citation Laureate in Biochemistry, with more than 7000 citations in the research literature the past two decades.

Martin's international reputation rests on his research into para-thyroid hormone related protein (PTHrP), which was originally regarded as a hormone. The PTHrP gene is upregulated in several cancers, and causes high blood calcium levels by coordinating the release of calcium from its main reservoir in bone, while inhibiting calcium excretion through its action on the kidneys.

Martin's research has shown that the protein is much more than a hormone: it is secreted by multiple tissues throughout the body, has multiple, localised functions, including transferring calcium across the placenta to the developing foetus.

Molecular machines

Molecular machines will be a major focus of the conference, with organisers predicting that Prof Keiichi Namba's video-illustrated talk on the structure and dynamics of the Salmonella flagellum will be the highlight. The Osaka University scientist heads the Namba Protonic NanoMachine Project, a multidisciplinary study which has shown that the bacterium's propulsion system comprises a rotary motor, coupled through a molecular universal joint to a flexible 'tail' that becomes a helical propeller when torque is applied (see 'Mr Namba's marvellous molecular machine').

Two pioneering investigators into the structure and function of the ribosome, Prof Vinka Ramakrishnan of the Medical Research Council's Laboratory of Molecular Biology, Cambridge, and Prof Joachim Frank, of the Department of Medical Sciences at the State University of New York, will address the conference's RNA-protein interactions session.

Prof Dick Wettenhall, director of the Bio21 Institute in Melbourne, said Ramakrishnan headed one of the three international groups that determined the structure of the 30S ribosomal subunit in bacteria in the 1980s. "Ramakrishnan's work led to an understanding of the details of how proteins are made, at the level of atomic structures," he says. "His work showed that the ribosome has RNA-rich and protein-rich regions, and nearly all of the functionality seemed to map to the RNA-rich regions. It highlighted, in a most graphic way, the important functionality of RNA."

Wettenhall says Ramakrishnan's pioneering discoveries subsequently illuminated how the major antibiotics streptomycin and erythromycin work by targeting ribosomal RNA, and the mechanisms of resistance to these antibiotics. There is now a major research focus on RNA-protein complexes as targets for new drugs -- the telomerase enzyme that renews the protective telomere 'caps' at the ends of chromosomes, is an RNA-protein complex of interest to developers of anti-cancer and anti-aging drugs.

Incredible power

Wettenhall says Joachim Frank had applied the technically demanding technique of cryo-electron microscopy to analyse of the structure of the ribosome in the mid-1990s, before the first X-ray crystallograms were made. Frank reconstructed a 3D image of the ribosome from thousands of 2D transmission electron micrographs of a single layer of bacterial ribosomes lying in random orientations.

According to Wettenhall, cryo-electron microscopy is used to determine the structure of biological complexes that cannot be crystallised intact. The sample must be cooled almost to absolute zero to prevent delicate protein-RNA structures being disrupted by the high-energy electron beam. He describes the analysis and reconstruction of the images as an enormous computational challenge. "Frank's structures have since been faithfully reproduced by x-ray crystallography. He's now working to obtain even higher resolution structures.

"The power of the technique is incredible," Wettenhall says. "Previously, textbooks showed the broad shape of ribosomes, as determined from scanning electron micrographs, but it wasn't until Frank's work that we began to see protein forms, and saw that the ribosome comprises two sub-units with a hole in the middle, where the messenger RNA goes. His structural work allowed us to visualise the process of decoding the mRNA and the assembly of the protein."

'Shotgun proteomics'

The conference's mass-imaging and proteomics sessions will hear mass spectrometry pioneer Prof John Yates of the Scripps Institute in La Jolla, California, describe a technique called 'shotgun proteomics'. Yates was a pioneer identifying proteins and determining their peptide sequences using mass spectrometry. Conference organiser Richard Simpson says Yates has now adapted these techniques to proteomics.

Shotgun proteomics applies to complex protein mixtures the genomics technique of applying powerful computer algorithms to reconstruct genomes by overlapping shared sequences from randomly cleaved DNA fragments. The technique allows researchers to analyse macromolecular complexes like yeast ribosomes, as a starting point for visualising the 3D structure of large complexes like ribosomes, the nuclear pore complex or the RNA-induced Silencing Complex (RISC) that mediates gene-silencing and anti-viral activity in the cells of higher organisms.

Simpson says eminent Japanese researcher Prof Yaeta Endo, director of the Cell-Free Science and Technology Research Centre at Ehime University in Matsuyama, Japan, who pioneered the development of the ubiquitous cell-free system for protein synthesis, will also be speaking at the Lorne conference.

Many major proteomics projects are now using Endo's ribosome-rich system to produce large quantities of extremely pure, properly folded proteins for high-resolution structural analyses. A full session of this year's conference will be given over to the four winners of the Lorne Young Investigator Award -- Simpson says the quality of the entries indicates the talks will be of a high standard.