SUPPRESSOR OF LLP1 1‐mediated C–terminal processing is critical for CLE19 peptide activity. (12th November 2013)

• Record Type: Journal Article
• Authors: Tamaki, Takayuki; Betsuyaku, Shigeyuki; Fujiwara, Masayuki; Fukao, Yoichiro; Fukuda, Hiroo; Sawa, Shinichiro
• Is Part Of: Plant journal. Volume 76:Number 6(2013:Dec.)
• Page Start: 970
• Page End: 981
• Publication Date: 2013-11-12
• Subjects: Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.12349
• Languages: English
• ISSNs: 0960-7412

Abstract

<abstract abstract-type="main" id="tpj12349-abs-0001"> <title>Summary</title> <p>Cell‐to‐cell communication is essential for the coordinated development of multicellular organisms. Members of the CLAVATA3/EMBRYO‐SURROUNDING REGION‐RELATED (CLE) family, a group of small secretory peptides, are involved in these processes in plants. Although post‐translational modifications are considered to be indispensable for their activity, the detailed mechanisms governing these modifications are not well understood. Here, we report that SUPPRESSOR OF LLP1 1 (SOL1), a putative Zn<sup>2+</sup> carboxypeptidase previously isolated as a suppressor of the <italic>CLE19</italic> over‐expression phenotype, functions in C–terminal processing of the CLE19 proprotein to produce the functional CLE19 peptide. Newly isolated <italic>sol1</italic> mutants are resistant to <italic>CLE19</italic> over‐expression, consistent with the previous report (Casamitjana‐Martinez, E., Hofhuis, H.F., Xu, J., Liu, C.M., Heidstra, R. and Scheres, B. (2003) <italic>Curr. Biol</italic>. 13, 1435–1441). As expected, our experiment using synthetic CLE19 peptide revealed that the <italic>sol1</italic> mutation does not compromise CLE signal transduction pathways <italic>per se</italic>. SOL1 possesses enzymatic activity to remove the C–terminal arginine residue of CLE19 proprotein <italic>in vitro</italic>, and SOL1‐dependent cleavage of the C–terminal arginine residue is necessary for CLE19 activity <italic>in vivo</italic>. Additionally, the endosomal localization of SOL1 suggests that this processing occurs in endosomes in the secretory pathway. Thus, our data indicate the importance of C–terminal processing of CLE proproteins to ensure CLE activities.</p> </abstract>