TY - JOUR
T1 - Role of fission yeast myosin I in organization of sterol-rich membrane domains
AU - Takeda, Tetsuya
AU - Chang, Fred
N1 - Funding Information:
We thank A. Chang, K. Gould, V. Sirotkin, and T. Pollard for valuable reagents, S. Salas-Pino and R. Daga for technical support, and members of our lab for discussion and advice. This work was supported by National Institutes of Health R01 GM056836 to F.C. and Postdoctoral Fellowships from Uehara Memorial Foundation to T.T.
PY - 2005/7/26
Y1 - 2005/7/26
N2 - Specialized membrane domains containing lipid rafts are thought to be important for membrane processes such as signaling and trafficking [1, 2]. An unconventional type I myosin has been shown to reside in lipid rafts and function to target a disaccharidase to rafts in brush borders of intestinal mammalian cells [3]. In the fission yeast Schizosaccharomyces pombe, distinct sterol-rich membrane domains are formed at the cell division site and sites of polarized cell growth at cell tips [4]. Here, we show that the sole S. pombe myosin I, myo1p, is required for proper organization of these membrane domains. myo1 mutants lacking the TH1 domain exhibit a uniform distribution of sterol-rich membranes all over the plasma membrane throughout the cell cycle. These effects are independent of endocytosis because myo1 mutants exhibit no endocytic defects. Conversely, overexpression of myo1p induces ectopic sterol-rich membrane domains. Myo1p localizes to nonmotile foci that cluster in sterol-rich plasma membrane domains and fractionates with detergent-resistant membranes. Because the myo1p TH1 domain may bind directly to acidic phospholipids, these findings suggest a model for how type I myosin contributes to the organization of specialized membrane domains.
AB - Specialized membrane domains containing lipid rafts are thought to be important for membrane processes such as signaling and trafficking [1, 2]. An unconventional type I myosin has been shown to reside in lipid rafts and function to target a disaccharidase to rafts in brush borders of intestinal mammalian cells [3]. In the fission yeast Schizosaccharomyces pombe, distinct sterol-rich membrane domains are formed at the cell division site and sites of polarized cell growth at cell tips [4]. Here, we show that the sole S. pombe myosin I, myo1p, is required for proper organization of these membrane domains. myo1 mutants lacking the TH1 domain exhibit a uniform distribution of sterol-rich membranes all over the plasma membrane throughout the cell cycle. These effects are independent of endocytosis because myo1 mutants exhibit no endocytic defects. Conversely, overexpression of myo1p induces ectopic sterol-rich membrane domains. Myo1p localizes to nonmotile foci that cluster in sterol-rich plasma membrane domains and fractionates with detergent-resistant membranes. Because the myo1p TH1 domain may bind directly to acidic phospholipids, these findings suggest a model for how type I myosin contributes to the organization of specialized membrane domains.
UR - http://www.scopus.com/inward/record.url?scp=22744458753&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=22744458753&partnerID=8YFLogxK
U2 - 10.1016/j.cub.2005.07.009
DO - 10.1016/j.cub.2005.07.009
M3 - Article
C2 - 16051179
AN - SCOPUS:22744458753
VL - 15
SP - 1331
EP - 1336
JO - Current Biology
JF - Current Biology
SN - 0960-9822
IS - 14
ER -