The beginning of the end of flagella

A new protein discovery sheds light on how chemical information is transported within cells. A group of researchers, which includes Dartmouth Professor of Biological Sciences Roger Sloboda, have found the protein EB1 in Chlamydomonas, a single-celled organism commonly used to study cell biology. Previous research has implicated EB1 in the progression of many colon cancers.

The research examined the chemical motors that power events in flagella, antenna-like structures on some cells. Specifically, the research focused on intraflagellar transport (IFT), the process where proteins required for flagellar growth and maintenance move within the flagella. The discovery of the protein EB1 at the tip of the flagella on Chlamydomonas furthers investigations into the role the protein plays in flagellar function and perhaps in regulating IFT itself.

The flagella beat rhythmically, moving the organism, and are made of nine double strands of microtubules and a central pair. According to Sloboda, similar IFT phenomena also take place in rod and cone cells of the human retina, in human kidney cells, and in nerve cells.

To determine where EB1 occurs in Chlamydomonas cells, the researchers cloned and sequenced the protein to make antibodies specific for EB1. The researchers found that the antibodies bound to the flagella tips, indicating that EB1 stays at the tip, and does not move along the length of the flagella.