Role of C. elegans TAT-1 protein in maintaining plasma membrane phosphatidylserine asymmetry.
The asymmetrical distribution of phospholipids on the plasma membrane is critical for maintaining cell integrity and physiology and for regulating intracellular signaling and important cellular events such as clearance of apoptotic cells. How phospholipid asymmetry is established and maintained is not fully understood. We report that the Caenorhabditis elegans P-type adenosine triphosphatase homolog, TAT-1, is critical for maintaining cell surface asymmetry of phosphatidylserine (PS). In animals deficient in tat-1, PS is abnormally exposed on the cell surface, and normally living cells are randomly lost through a mechanism dependent on PSR-1, a PS-recognizing phagocyte receptor, and CED-1, which contributes to recognition and engulfment of apoptotic cells. Thus, tat-1 appears to function in preventing appearance of PS in the outer leaflet of plasma membrane, and ectopic exposure of PS on the cell surface may result in removal of living cells by neighboring phagocytes.
Darland-Ransom
Monica
M
Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.
Wang
Xiaochen
X
Sun
Chun-Ling
CL
Mapes
James
J
Gengyo-Ando
Keiko
K
Mitani
Shohei
S
Xue
Ding
D
D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism; D032342:Muscle Cells / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D010587:Phagocytosis; D010718:Phosphatidylserines / Q000378:metabolism*; D049294:Phospholipid Transfer Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; D010718:Phosphatidylserines; D049294:Phospholipid Transfer Proteins; D011993:Recombinant Fusion Proteins; C522446:TAT-1 protein, C elegans