Centrin 3 is an inhibitor of centrosomal Mps1 and antagonizes centrin 2 function.
Centrins are a family of small, calcium-binding proteins with diverse cellular functions that play an important role in centrosome biology. We previously identified centrin 2 and centrin 3 (Cetn2 and Cetn3) as substrates of the protein kinase Mps1. However, although Mps1 phosphorylation sites control the function of Cetn2 in centriole assembly and promote centriole overproduction, Cetn2 and Cetn3 are not functionally interchangeable, and we show here that Cetn3 is both a biochemical inhibitor of Mps1 catalytic activity and a biological inhibitor of centrosome duplication. In vitro, Cetn3 inhibits Mps1 autophosphorylation at Thr-676, a known site of T-loop autoactivation, and interferes with Mps1-dependent phosphorylation of Cetn2. The cellular overexpression of Cetn3 attenuates the incorporation of Cetn2 into centrioles and centrosome reduplication, whereas depletion of Cetn3 generates extra centrioles. Finally, overexpression of Cetn3 reduces Mps1 Thr-676 phosphorylation at centrosomes, and mimicking Mps1-dependent phosphorylation of Cetn2 bypasses the inhibitory effect of Cetn3, suggesting that the biological effects of Cetn3 are due to the inhibition of Mps1 function at centrosomes.
Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210.
Dwitiya B
DB
Sawant
Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210.
Shubhra
S
Majumder
Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210.
Jennifer L
JL
Perkins
Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210.
Ching-Hui
CH
Yang
Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom.
Patrick A
PA
Eyers
Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 fisk.13@osu.edu.
Harold A
HA
Fisk
D000595:Amino Acid Sequence; D002135:Calcium-Binding Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002478:Cells, Cultured; D002502:Centrioles / Q000378:metabolism; D018385:Centrosome / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
C472752:CETN2 protein, human; C107745:CETN3 protein, human; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C075840:TTK protein, human