New building block in cells

Zemer Gitai, at Princeton University, and scientists from the California Institute of Technology have published results of new research into how a metabolic enzyme in bacteria forms cytoplasmic filaments that affect bacterial cell shape. Gitai describes the findings as follows: - "We have discovered that an enzyme that has a role in basic cellular metabolism (CtpS, the enzyme that makes the essential nucleotide CTP), also forms cytoskeletal filaments that can play a structural role in regulating cell shape. "I'm very excited about this work since it changes a lot of our thinking about both metabolism and the cytoskeleton, and provides a clue about how the cytoskeleton might have evolved in the first place. The work connects two exciting areas of research: cell shape formation and metabolism. "Cytoskeletal proteins serve as cellular building blocks, and the cytoskeleton has long been thought to consist of just three canonical members: actin, tubulin, and intermediate filaments. By using a novel imaging-based screening approach, we found that the metabolic enzyme that makes CTP, CTP Synthase (CtpS), also plays a previously-unappreciated role as a cytoskeletal protein by polymerizing into filaments that regulate the cell shape of the curved bacterium Caulobacter crescentus. "The CtpS protein is found in all living organisms from bacteria to humans, suggesting that this could be a widespread phenomenon.