Proteomics a new language

A Proteomics Glossary

Bill Snyder
Published: February, 2003

The term “proteome” was coined by Australian researchers in the mid-1990s to describe all the PROTEins expressed by the genOME, the complete set of genetic material necessary for life. Proteomics, then, is the study of the expression, function and interaction of proteins in health and disease.

Here’s a guide to proteins we included in our cover illustration:

ApoE – apolipoprotein E, a protein involved in the transport of cholesterol and other fatty molecules. One form of this protein is a major risk factor for Alzheimer’s disease.

CD4 – a protein on white blood cells that binds to HIV, the virus that causes AIDS.

Cytochrome P-450 – a class of enzymes that play important roles in the metabolism of drugs and toxins in the liver.

COX – cyclooxygenase, an enzyme that exists in at least two forms, and which exerts a wide variety of effects in different tissues through the production of locally acting hormones called prostaglandins.

EGFR – epidermal growth factor receptor, a protein that plays a role in signaling cell growth, including cancer growth.

G proteins – known for their ability to bind guanine nucleotides. They transmit signals from a large class of proteins called G protein-coupled receptors (GPCRs).
Together, G proteins and GPCRs play a role in a wide range of physiological functions, including the regulation of blood pressure, the production of glucose by the liver, and the transmission of signals between nerve cells in the brain.

Ion channel – proteins that allow ions, or electrically charged molecules like sodium, calcium or chloride to pass through cell membranes. Ion channels generate and orchestrate the complex language of electrical signals essential to the function of muscles, lungs, heart, brain and other vital organs.

Kinase – a family of enzymes that attach phosphate groups to specific amino acids in proteins. Tyrosine kinases, for example, attach phosphate groups to tyrosine, a key event in many “signaling pathways,” including blood sugar regulation by insulin and cell growth triggered by epidermal growth factor.

Nuclear pore protein – groups of proteins allow molecules to pass in and out of the nucleus of the cell.

PAI-1 – plasminogen activator inhibitor, a protein that can block natural clot-busting enzymes in the body, including tissue-type plasminogen activator (t-PA). High levels of PAI-1 are therefore a risk factor for cardiovascular disease.

PSA – prostate-specific antigen, a protein marker found in the blood that is associated with prostate cancer.

TGF-beta – transforming growth factor beta, a protein first identified in cancer cells that suppresses cell growth.