Diverse roles of SERK family genes in plant growth, development and defense response

Abstract

Plant receptor-like protein kinases (RLKs) are transmembrane proteins with an extracellular domain and an intracellular kinase domain, which enable plant perceiving diverse extracellular stimuli to trigger the intracellular signal transduction. The somatic embryogenesis receptor kinases (SERKs) code the leucine-rich-repeat receptor-like kinase (LRR-RLK), and have been demonstrated to associate with multiple ligand-binding receptors to regulate plant growth, root development, male fertility, stomatal development and movement, and immune responses. Here, we focus on the progress made in recent years in understanding the versatile functions of Arabidopsis SERK proteins, and review SERK proteins as co-receptor to perceive different endogenous and environmental cues in different signaling pathway, and discuss how the kinase activity of SERKs is regulated by various modification.

Transcriptional Analysis of serk1 and serk3 Coreceptor Mutants

“…Current models indicate that SERKs contribute to ligand binding by forming an integral part of the ligand-binding pocket (Santiago et al, 2013;Sun et al, 2013). This is most likely also the case for an increasing number of main ligand-perceiving receptors found to employ members of the SERK family in different plant families (aan den Toorn et al, 2015;Wang et al, 2015;Fan et al, 2016). SERK1, SERK3 (BAK1), and SERK4 (BKKI1) function as coreceptors of BRASSINOSTEROID INSENSITIVE1 (BRI1), which is the main ligand-perceiving receptor for brassinosteroids (BRs) in Arabidopsis (Wang et al, 2001;Li et al, 2002;Karlova et al, 2006;.…”

Look Closely, the Beautiful May Be Small: Precursor-Derived Peptides in Plants

“…In the canonical mode of receptor kinase signaling, ligand binding by receptor kinase extracellular domains activates the intracellular protein kinase domain of the receptor. Auto-and transphosphorylation events often result between receptors, possible coreceptors, and activation of other downstream components, leading to a final cellular outcome (46,64,192,217) (Figure 2b). Interestingly, growing numbers of receptors have been found to regulate multiple biological functions.…”

“…A single receptor can also perceive multiple peptides that may act in an antagonistic manner, as with EPF2 and STOMAGEN/EPF-LIKE 9 (EPFL9), both of which bind to ER and the RLP TOO MANY MOUTHS (TMM) to control stomatal patterning in the leaf epidermis (91,98). Furthermore, different ligand-receptor pairs often share common downstream signaling components, such as coreceptors (e.g., BAK1), and identical mitogenactivated protein kinases (MAPK) signaling networks (46,213). Given the commonality of signaling components, it becomes relevant to investigate how signal specificity and cellular output are derived for distinct biological processes.…”

“…The SERK family of LRR-RLKs functions as coreceptors for several plant LRR-RLKs, and SERKs interact with receptors that include PSK RECEPTOR 1 (PSKR1), PEP RECEPTOR 1, BRI1, and FLAGELLIN SENSITIVE 2 (FLS2) (25,60,94,123,159,183), raising the question of how a common coreceptor can give rise to a wide range of cellular outputs. A way to achieve this is by employing a large range of residues in the SERK extracellular domain to interact with different receptors, in some cases binding directly to both ligand and receptor, as was first shown for FSL2 and BAK1, SERK1 and BRI1, and in other cases interacting with only the receptor, such as the PSK-PSKR1-SERK1 complex (46,64,113,159,183,203). Besides the SERKs, there are other RLKs in Arabidopsis that have similar short extracellular structures.…”

Methylation Analysis of CpG Islands in Pineapple SERK1 Promoter

“…Only somatic embryogenesis receptor kinases (SERKs) have been found to play an important role in the earlier transition from somatic cells to embryonic cells [7][8][9]. This small gene family of receptor-like kinases plays diverse roles in plants [10,11]. Among the SERK family, SERK1 is regarded as a SE marker gene of pineapple and other plants [12,13].…”