High impact information on CLV3

• Our analysis of the interactions between these key regulators indicates that (1) the CLV genes repress WUS at the transcript level and that (2) WUS expression is sufficient to induce meristem cell identity and the expression of the stem cell marker CLV3 [1].
• CLV1 negatively regulates formation of the shoot and floral meristems through cell-cell communication involving the CLV3 peptide [2].
• Dependence of stem cell fate in Arabidopsis on a feedback loop regulated by CLV3 activity [3].
• Recent studies in Arabidopsis have identified factors that contribute to meristem structure and identity, such as CLAVATA1, CLAVATA3, and SHOOTMERISTEMLESS, which act in both shoot and flower meristems, as well as LEAFY and APETALA1 which specifically determine a floral fate [4].
• Moreover, the effects of CLV3 overexpression that result in the elimination of SAM activity were abolished in the shd mutant, indicating that CLV function is dependent on SHD function [5].

Biological context of CLV3

• Here, we show that in vitro application of synthetic 14-amino acid peptides, CLV3p, CLE19p, and CLE40p, corresponding to the conserved CLE motif, mimics the overexpression phenotype [6].
• Genetic analysis indicates that CLV1, which encodes a receptor kinase, acts with CLV3 to control the balance between meristem cell proliferation and differentiation [7].
• Whereas cna single mutant plants exhibit subtle defects in meristem development, clv cna double mutants develop massively enlarged apices that display early loss of organogenesis, misexpression of WUS and CLV3, and eventual differentiation of the entire apex [8].
• Homeostasis of the stem cell population may be achieved through feedback regulation, whereby changes in stem cell number result in corresponding changes in CLV3 expression levels, and adjustment of WUS expression via the CLV signal transduction pathway [9].
• We show here that CLV3 restricts its own domain of expression (the CZ) by preventing differentiation of peripheral zone cells (PZ), which surround the CZ, into CZ cells and restricts overall SAM size by a separate, long-range effect on cell division rate [10].

Anatomical context of CLV3

• While CLV3 transcripts are confined to stem cells of the shoot system, CLE40 is expressed at low levels in all tissues, including roots [11].

Associations of CLV3 with chemical compounds

• A hydroxyl 12-amino acid peptide derived from the conserved CLE motif of CLV3 promotes cell differentiation, whereas another CLE-derived peptide suppresses the differentiation [12].
• Despite the fact that structural features of LRR-RKs are fairy similar, five available ligand molecules for LRR-RKs are structurally diverse, from steroids (brassinolides) to peptides (phytosulfokine and systemin) and secreted proteins (CLV3) [13].
• A bioassay of single-cell transdifferentation demonstrates that a dodecapeptide with two hydroxyproline residues is the functional product of genes from the CLE family, which includes CLAVATA3 in Arabidopsis [14].

Physical interactions of CLV3

• More than 75% of CLV3 in cauliflower extracts is bound with CLV1, consistent with hypotheses of ligand sequestration [15].

Regulatory relationships of CLV3

• In accordance with this decrease in meristem size, application of CLV3p to in vitro-grown clv3 seedlings restricts the expression of the stem cell-promoting transcription factor WUSCHEL [16].
• CLV3 acts nonautonomously in meristems and is expressed at the meristem surface overlying the CLV1 domain [7].

Other interactions of CLV3

• The 14-amino acid CLV3, CLE19, and CLE40 peptides trigger consumption of the root meristem in Arabidopsis through a CLAVATA2-dependent pathway [6].
• The 14-amino acid CLE41, CLE42, CLE43 and CLE44 peptides trigger the proliferation of procambial cells in vascular tissues [17]
• In other cases, minor QTLs for floral organ number (lcn2.2) and (stn11.2) co-localized with a CLV1 paralog and with the syntenic region containing the CLV3 gene in Arabidopsis, respectively [18].
• A recent study on CLV3 shows that the CLV3/ESR (CLE) motif, together with the adjacent C-terminal sequence, is sufficient to execute CLV3 function when fused behind an N-terminal sequence of ERECTA [16].
• Other components of the CLV1 signaling pathway include the secreted putative ligand CLV3 and the receptor-like protein CLV2 [19].
• The root meristem also contains a stem cell organizer, and here we show that localized overexpression in roots of CLE19, encoding a CLV3 homolog, restricts the size of the root meristem [20].
• CLE induced procambial cell proliferation is regulated by the phytohormone auxin [17].

Analytical, diagnostic and therapeutic context of CLV3

• Molecular cloning reveals that FON2 encodes a small secreted protein, containing a CLE domain, that is closely related to CLAVATA3 in Arabidopsis thaliana [21].

References