Movement is what sustains life. Organisms need to move to find food, seek shelter and to reproduce. Mobility is also essential inside organisms where cells are continuously dividing and migrating. There is also unceasing movement inside every cell where myriads of molecules are being trafficked, and cellular compartments of all shapes and sizes shifted. What keeps things moving? Years ago, scientists discovered a protein they coined actin. Actin is a small globular protein that has many different roles in eukaryotic cells. One characteristic feature is its capacity to polymerize into microfilaments that stretch from one end of a cell to another to form the cell's cytoskeleton - which speaks for itself. Though the formation of a cell's cytoskeleton is perhaps considered as actin's fundamental role in the cytoplasm, the protein is also involved in many other activities, one of which is mobility. Actin is also present in the nucleus but, until recently, scientists believed that microfilaments did not form there. It turns out that they do: damaged DNA seems to be oriented towards repair centres thanks to actin microfilaments whose growth is prompted by a protein complex known as Arp2/3.
More from Protein Spotlight
Tales From A Small World
Tales From A Small World is a collection of the first hundred articles which originally appeared on this site. Published in September 2009, the book is enriched by poems from the Dublin poet, Pat Ingoldsby. Learn more and order your copy online.
Journey Into A Tiny World
« Globin and Poietin set out to save Lily's life. But time is running short and they can't find the marrow... Here is the tale of their courage, fun and laughter on a journey that takes them deep into the tiniest of worlds.» For children. Learn more and order your copy online.
Snapshot : Countins
It is crucial for a tissue to stop growing, once there is enough of it. The proportions of every living entity are predefined for a reason – and not simply for the sake of aesthetics. If our brains didn’t stop growing, we would become top heavy and our heads would tilt and droop helplessly on one side, making life somewhat inconvenient. The same goes for the slime mould Dictyostelium discoideum.
A little bit of praise!
“I recently stumbled upon your columns. Let me congratulate you on achieving the near impossible, for your articles have enabled me to successfully marry IT with the Life Sciences and better explain the concepts of bioinformatics to those who are not in the know of the field.
Your articles are very well written, lucid, and contain just enough information to excite the reader to want to learn more about the topic being discussed. They fall in a very rare category where they are accessible to everyone, from the undergraduate students to research students who want to have a basic idea of the topics being discussed. Some of your articles, like "Our hollow architecture" and "Throb" are outstanding pieces.
I would highly recommend your articles as a necessary reading in undergrad classes to get students inspired about the various avenues of research.”