TY - JOUR
T1 - Arabidopsis thaliana rapid alkalinization factor 1-mediated root growth inhibition is dependent on calmodulin-like protein 38
AU - Campos, Wellington F.
AU - Dressano, Keini
AU - Ceciliato, Paulo H.O.
AU - Carlos Guerrero-Abad, Juan
AU - Leonir Silva, Aparecida
AU - Fiori, Celso S.
AU - Do Canto, Amanda Morato
AU - Bergonci, Tabata
AU - Claus, Lucas A.N.
AU - Silva-Filho, Marcio C.
AU - Moura, Daniel S.
N1 - Publisher Copyright:
© 2018 by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2018/2/9
Y1 - 2018/2/9
N2 - Arabidopsis thaliana rapid alkalinization factor 1 (AtRALF1) is a small secreted peptide hormone that inhibits root growth by repressing cell expansion. Although it is known that AtRALF1 binds the plasma membrane receptor FERONIA and conveys its signals via phosphorylation, the AtRALF1 signaling pathway is largely unknown. Here, using a yeast two-hybrid system to search for AtRALF1-interacting proteins in Arabidopsis, we identified calmodulin-like protein 38 (CML38) as an AtRALF1-interacting partner. We also found that CML38 and AtRALF1 are both secreted proteins that physically interact in a Ca2+-And pH-dependent manner. CML38-knockout mutants generated via T-DNA insertion were insensitive to AtRALF1, and simultaneous treatment with both AtRALF1 and CML38 proteins restored sensitivity in these mutants. Hybrid plants lacking CML38 and having high accumulation of the AtRALF1 peptide did not exhibit the characteristic short-root phenotype caused by AtRALF1 overexpression. Although CML38 was essential for AtRALF1-mediated root inhibition, it appeared not to have an effect on the AtRALF1-induced alkalinization response. Moreover, acridinium-labeling of AtRALF1 indicated that the binding of AtRALF1 to intact roots is CML38-dependent. In summary, we describe a new component of the AtRALF1 response pathway. The new component is a calmodulin-like protein that binds AtRALF1, is essential for root growth inhibition, and has no role in AtRALF1 alkalinization.
AB - Arabidopsis thaliana rapid alkalinization factor 1 (AtRALF1) is a small secreted peptide hormone that inhibits root growth by repressing cell expansion. Although it is known that AtRALF1 binds the plasma membrane receptor FERONIA and conveys its signals via phosphorylation, the AtRALF1 signaling pathway is largely unknown. Here, using a yeast two-hybrid system to search for AtRALF1-interacting proteins in Arabidopsis, we identified calmodulin-like protein 38 (CML38) as an AtRALF1-interacting partner. We also found that CML38 and AtRALF1 are both secreted proteins that physically interact in a Ca2+-And pH-dependent manner. CML38-knockout mutants generated via T-DNA insertion were insensitive to AtRALF1, and simultaneous treatment with both AtRALF1 and CML38 proteins restored sensitivity in these mutants. Hybrid plants lacking CML38 and having high accumulation of the AtRALF1 peptide did not exhibit the characteristic short-root phenotype caused by AtRALF1 overexpression. Although CML38 was essential for AtRALF1-mediated root inhibition, it appeared not to have an effect on the AtRALF1-induced alkalinization response. Moreover, acridinium-labeling of AtRALF1 indicated that the binding of AtRALF1 to intact roots is CML38-dependent. In summary, we describe a new component of the AtRALF1 response pathway. The new component is a calmodulin-like protein that binds AtRALF1, is essential for root growth inhibition, and has no role in AtRALF1 alkalinization.
UR - http://www.scopus.com/inward/record.url?scp=85041962765&partnerID=8YFLogxK
U2 - 10.1074/jbc.M117.808881
DO - 10.1074/jbc.M117.808881
M3 - Journal article
C2 - 29282286
AN - SCOPUS:85041962765
SN - 0021-9258
VL - 293
SP - 2159
EP - 2171
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 6
ER -