Protein interactions among eyespot proteins

Mary Rose Lamb1, Students of the Biology 404 class1, Telsa Mittelmeier2, and Carol Dieckmann2

1Department of Biology, University of Puget Sound, Tacoma, Washington;2 Department of Biochemistry, University of Arizona, Tucson, Arizona

The eyespot of Chlamydomonas reinhardtii is broken down and reformed at each cell division. The new eyespots are located just clockwise of the daughter four-membered microtubule rootlets in the daughter cells. Using a genetic approach, we have identified four genes required for correct assembly and placement of the eyespot. Mutations in EYE2 or EYE3 result in an eyeless phenotype. Mutations in MIN1 produce small, misplaced eyespots and those in MLT1 result in cells with two or more eyespots. The proteins encoded by these genes are all novel proteins and their function in assembly of the organelle is not immediately apparent. Each of the proteins does contain recognizable domains that may be required for eyespot assembly. As a portion of the Molecular Biology laboratory course at the University of Puget Sound, students have cloned significant domains into plasmids for a yeast two hybrid experiment. We have cloned the thioredoxin domain and LysM domain from EYE2, the C2 domain and LysM domains of MIN1, and the serine-threonine kinase domain ofEYE3. These domains will be tested for interactions with each other and with the photoreceptor, channelrhodopsin-1 (ChR1).

e-mail address of presenting author: mrlamb@ups.edu