The RLK/Pelle family of kinases

Abstract

The RLK/Pelle class of proteins kinases is composed of over 600 members in Arabidopsis. Many of the proteins in this family are receptor-like kinases (RLK), while others have lost their extracellular domains and are found as cytoplasmic kinases. Proteins in this family that are RLKs have a variety of extracellular domains that drive function in a large number of processes, from cell wall interactions to disease resistance to developmental control. This review will briefly cover the major subclasses of RLK/Pelle proteins and their roles. In addition, two specific groups on RLKs will be discussed in detail, relating recent findings in Arabidopsis and how well these conclusions have been able to be translated to agronomically important species. Finally, some details on kinase activity and signal transduction will be addressed, along with the mystery of RLK/Pelle members lacking kinase enzymatic activity.

LYR3, a high‐affinity LCO‐binding protein of Medicago truncatula, interacts with LYK3, a key symbiotic receptor

“…Two prevalent extracellular protein domains consist of either leucine-rich repeats (LRRs) or lysin motifs (LysMs), which might interact with peptides or with N-acetyl-D-glucosamine (GlcNAc)-containing compounds, respectively [1,2].…”

Computational Identification of Conserved Domains from Genomic Survey Sequences in Green Gram [Vigna radiata (L.) R. Wilczek]

“…LRR-containing proteins from plants have diverse overall structures and functions. Several classes contain LRR-containing receptor-like kinases (LRR-RLKs) [1,16], LRR-containing receptor-like proteins (LRR-RLPs) [10], nucleotide binding site LRR (NBS-LRR) proteins [7,26] and PolyGalacturonase Inhibiting Proteins (PGIPs) [8,9,30]. They provide an early warning system for the presence of potential pathogens and activate protective immune signaling in plants [20,18,35].…”

Stem Cell Signaling in Immunity and Development

“…We observed that the endogenously modified 12-amino-acid (aa) CLV3p triggered similar responses to flg22 (the conserved 22-aa peptide of bacterial flagellin) in mesophyll protoplasts (Asai et al 2002;Shan et al 2008;Lee et al 2011). This finding was unexpected because CLV3p is normally expressed, secreted, and processed by stem cells to control SAM maintenance via CLV1, CLV2, and other receptors (Kondo et al 2006;Jun et al 2008;Gish and Clark 2011;Matsubayashi 2011;Aichinger et al 2012 (Asai et al 2002;He et al 2006;Shan et al 2008;Boller and Felix 2009;Boudsocq et al 2010). Highly purified CLV3p synthesized by different sources displayed the same activities, ruling out the possibility of contamination.…”

“…Because CLV3p is specifically expressed and secreted from stem cells of the SAM (Kondo et al 2006;Jun et al 2008;Gish and Clark 2011;Matsubayashi 2011;Aichinger et al 2012), it is critical to examine CLV3p-FLS2 signaling in the SAM to evaluate its physiological relevance. Using quantitative reverse transcription -polymerase chain reaction (qRT-PCR) analysis with isolated SAM tissues, CLV3p clearly triggered two parallel signaling pathways in the SAM.…”

“…Molecular genetic and biochemical advances during past decades have revealed that peptides secreted and processed from and around stem cells have pivotal roles in controlling cell identity and developmental processes through multiple receptor kinase complexes in the SAM ( Fig. 1) (Kondo et al 2006;DeYoung and Clark 2008;Jun et al 2008;De Smet et al 2009;Guo et al 2010;Kinoshita et al 2010;Gish and Clark 2011;Matsubayashi 2011;Aichinger et al 2012;Perales and Reddy 2012;Song et al 2012). However, little is known about the dynamic biochemical, molecular, and cellular events and regulatory components constituting the primary signaling processes after peptide ligand perception by receptor kinases in the SAM (Betsuyaku et al 2011;Perales and Reddy 2012).…”