Protein: Protein BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE (Q5BPF3)
Organism: Arabidopsis thaliana (Mouse-ear cress)
Function: Regulates asymmetric cell division (ACD), especially in stomatal-lineage cells, probably by modulating accumulation and subcellular polarization of POLAR and SPCH. Mediates an attenuation of MAPK signaling upon polarization of POLAR and ASK7/BIN2 in stomatal lineage ground cells (SLGCs) undergoing ACD, and relieves BIN2 inhibition of SPCH in the nucleus. When phosphorylated, functions as a scaffold and recruits the MAPKKK YODA, MPK3 and MPK6 to spatially reorganize the MAPK signaling pathway at the cortex of cells undergoing ACD. Cortical polarization leads to elevated nuclear MPK6 signaling and lowered SPCH abundance in one of the two daughter cells, thus differentiating the two daughter cells after ACD.
Subcellular location: Cytoplasm {ECO:0000269|PubMed:25843888, ECO:0000269|PubMed:27422992, ECO:0000269|PubMed:30429609}. Nucleus {ECO:0000255|PROSITE-ProRule:PRU00768, ECO:0000269|PubMed:19523675, ECO:0000269|PubMed:21903812, ECO:0000269|PubMed:25843888, ECO:0000269|PubMed:27422992, ECO:0000269|PubMed:27746029, ECO:0000269|PubMed:30429609}. Cytoplasm, cell cortex {ECO:0000269|PubMed:19523675, ECO:0000269|PubMed:21903812, ECO:0000269|PubMed:25843888, ECO:0000269|PubMed:27422992, ECO:0000269|PubMed:27746029, ECO:0000269|PubMed:30429609}. Cell membrane {ECO:0000269|PubMed:27746029}; Peripheral membrane protein {ECO:0000269|PubMed:27746029}. Note=Dynamic and highly polarized subcellular localization at the cortical polarity in a phosphorylation status-dependent manner (PubMed:19523675, PubMed:21903812, PubMed:25843888, PubMed:27422992, PubMed:27746029, PubMed:30429609). Polarity is only exhibited by one daughter cell after an asymmetric cell division (PubMed:27746029). ASK7/BIN2-mediated nuclear exclusion (PubMed:30429609). First localized to the nucleus in asymmetric cell division (ACD) precursors (PubMed:30429609). In asymmetrically dividing stomatal-lineage cells, before division, accumulates in a polarized crescent at the cell periphery (e.g. meristemoid mother cells (MMCs)), and, after division, localizes differentially to the nucleus (e.g. in meristemoids) and a peripheral crescent in self-renewing cells and their sisters (e.g. stomatal lineage ground cell (SLGC)) (PubMed:19523675, PubMed:25843888, PubMed:27422992, PubMed:30429609). Localized in the cell periphery at a position that minimizes the inverse distance from all points along the new division boundaries (PubMed:21903812). {ECO:0000269|PubMed:19523675, ECO:0000269|PubMed:21903812, ECO:0000269|PubMed:25843888, ECO:0000269|PubMed:27422992, ECO:0000269|PubMed:27746029, ECO:0000269|PubMed:30429609}.
Interaction partners:
- Transcription factor SPEECHLESS
- Protein Brevis radix-like 2
- Mitogen-activated protein kinase kinase kinase YODA
- Protein EPIDERMAL PATTERNING FACTOR 2
- Transcription factor MUTE
- Protein EPIDERMAL PATTERNING FACTOR 1
- EPIDERMAL PATTERNING FACTOR-like protein 9
- Protein TOO MANY MOUTHS
- Kinesin-like protein KIN-UA
- LRR receptor-like serine/threonine-protein kinase ERL1
Sequence:
MASQWTIPKLVTWRVRDWASCFLACKIPLDGDEDGANNNGNTTNNNNLTFKRIKRKIKSTKKKRSERKLSLSPPGTRHHHLHLRSSSVSPTTSGSQHRRLSWPQPPVSEESGFIVFCFDREDGGFDVVKEGKQEKKETESSSEKSPRTVNRKLIYGDQGVGGTEKNNSPETKGTEQDQNDNTSCQGTKDVSSDVTERTKEEEDIDASDKSSGSSHSDEGRGSFAFPILGVEWMGSPAKMPESDDLSPKKQKPVALGFQCCRF