C2 domain protein MIN1 promotes eyespot organization in Chlamydomonas reinhardtii

Telsa M. Mittelmeier, Peter Berthold, Avihai Danon, Mary Rose Lamb, Alexander Levitan, Michael E. Rice, Carol L. Dieckmann

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Assembly and asymmetric localization of the photosensory eyespot in the biflagellate, unicellular green alga Chlamydomonas reinhardtii requires coordinated organization of photoreceptors in the plasma membrane and pigment granule/thylakoid membrane layers in the chloroplast. min1 (mini-eyed) mutant cells contain abnormally small, disorganized eyespots in which the chloroplast envelope and plasma membrane are no longer apposed. The MIN1 gene, identified here by phenotypic rescue, encodes a protein with an N-terminal C2 domain and a C-terminal LysM domain separated by a transmembrane sequence. This novel domain architecture led to the hypothesis that MIN1 is in the plasma membrane or the chloroplast envelope, where membrane association of the C2 domain promotes proper eyespot organization. Mutation of conserved C2 domain loop residues disrupted association of the MIN1 C2 domain with the chloroplast envelope in moss cells but did not abolish eyespot assembly in Chlamydomonas. In min1 null cells, channelrhodopsin-1 (ChR1) photoreceptor levels were reduced, indicating a role for MIN1 in ChR1 expression and/or stability. However, ChR1 localization was only minimally disturbed during photoautotrophic growth of min1 cells, conditions under which the pigment granule layers are disorganized. The data are consistent with the hypothesis that neither MIN1 nor proper organization of the plastidic components of the eyespot is essential for localization of ChR1.

Original languageEnglish (US)
Pages (from-to)2100-2112
Number of pages13
JournalEukaryotic Cell
Volume7
Issue number12
DOIs
StatePublished - Dec 1 2008

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology

Fingerprint Dive into the research topics of 'C2 domain protein MIN1 promotes eyespot organization in Chlamydomonas reinhardtii'. Together they form a unique fingerprint.

  • Cite this

    Mittelmeier, T. M., Berthold, P., Danon, A., Lamb, M. R., Levitan, A., Rice, M. E., & Dieckmann, C. L. (2008). C2 domain protein MIN1 promotes eyespot organization in Chlamydomonas reinhardtii. Eukaryotic Cell, 7(12), 2100-2112. https://doi.org/10.1128/EC.00118-08