Transport to the Cell Surface of Chlamydomonas: Mastigonemes as a Marker for the Flagellar Membrane

Abstract

We have begun experiments to determine how proteins are targeted to different cell surface domains of the unicellular green alga, Chlamydomonas. Though contiguous, the flagellar membrane and plasma membrane of Chlamydomonas define physically and biochemically distinct compartments. The plasma membrane is surrounded by the cell wall, constructed from hydroxyproline rich glycoproteins, and a set of inducible enzymes, such as carbonic anhydrase and arylsulfatase,are specifically secreted into the periplasmic space. In contrast, the flagellar membrane is not surrounded by the cell wall and contains proteins not found on the plasma membrane, including agglutinins used for adhesion during mating, and a 350 kD protein required for gliding motility on solid substrates. (For reviews, see Harris, 1989, and Bloodgood, 1990.)