The covalent attachment of ubiquitin is an important determinant for selective protein degradation by the 26S proteasome in plants and animals. specificity ubiquitination often controlled ubiquitin-protein ligases (or E3s), which facilitate transfer to appropriate targets. One ligase type, SCF E3s are composed four proteins, cullin1/Cdc53, Rbx1/Roc1/Hrt1, Skp1, F-box protein. protein, identifies targets, binds Skp1 component complex through a degenerate N-terminal ≈60-aa motif called F-box....

Ubiquitination of various intracellular proteins by ubiquitin-protein ligases (or E3s) plays an essential role in eukaryotic cell regulation primarily through its ability to selectively target for degradation the 26S proteasome. Skp1, Cullin, F-box (SCF) complexes are one influential E3 class that use deliver targets a core ligase activity provided and Rbx1 subunits. Almost 700 can be found Arabidopsis, indicating SCF E3s likely play pervasive plant physiology development. Here, we describe...

Abstract Ethylene signaling in Arabidopsis thaliana converges on the ETHYLENE-INSENSITIVE3 (EIN3)/EIN3-Like (EIL) transcription factors to induce various responses. EIN3 BINDING F-BOX1 (EBF1) and EBF2 were recently shown function ethylene perception by regulating EIN3/EIL turnover. In absence of ethylene, possibly other EIL proteins are targeted for ubiquitination subsequent degradation Cullin 1–based E3 complexes containing EBF1 2. appears block this ubiquitination, allowing levels rise...

Selective modification of proteins by ubiquitination is directed diverse families ubiquitin-protein ligases (or E3s). A large collection E3s use Cullins (CULs) as scaffolds to form multisubunit E3 complexes in which the CUL binds a target recognition subcomplex and RBX1 docking protein, delivers activated ubiquitin moiety. Arabidopsis rice contain isoforms, indicating that multiple CUL-based exist plants. Here we show CUL3a CUL3b associate with members broad complex/tramtrack/bric-a-brac...

Abstract Stem cell maintenance and differentiation are tightly regulated in multicellular organisms. In plants, proper control of the stem populations is critical for extensive postembryonic organogenesis. The Arabidopsis thaliana protein phosphatase type 2C proteins POLTERGEIST (POL) PLL1 essential both root shoot cells. Specifically, POL required specification key asymmetric divisions during initiation maintenance. known to be integral components CLE/WOX signaling pathways, but location...

Abstract The photorespiratory pathway is comprised of enzymes localized within three distinct cellular compartments: chloroplasts, peroxisomes, and mitochondria. Photorespiratory are encoded by nuclear genes, translated in the cytosol, targeted into these subcellular compartments. One likely means which to regulate expression genes encoding coordinated temporal control. We have previously shown Arabidopsis that a circadian clock regulates both chloroplastic (Rubisco small subunit Rubisco...

Stem cell establishment and maintenance are essential for the largely post-embryonic developmental patterning that occurs in higher plants. Plant embryos establish two stem populations at shoot root meristems which then function to continuously generate tissues, respectively. Research has uncovered entirely separate sets of regulators cells, raising questions about origin later-evolving meristem relationship between meristems. We have recently demonstrated related Arabidopsis phosphatases...

The development of plants from seedlings to mature adult organisms requires the precise maintenance stem cell populations at meristems. In Arabidopsis, CLAVATA (CLV) pathway is vital for homeostatic regulation shoot and floral Two components this are protein phosphatase type 2 C proteins, POLTERGEIST (POL) PLL1, which positively regulate specification. Recent studies by our laboratory demonstrated that POL PLL1 not only meristem but also other essential developmental processes including...

The CLAVATA (CLV) signaling pathway is essential for shoot meristem homeostasis in Arabidopsis. CLV acts to limit the expression domain of stem cell-promoting gene WUSCHEL (WUS). closely related receptor-kinases CLV1 and BAM1 are key components this pathway; however, downstream factors that link receptors WUS regulation poorly understood. Arabidopsis At5g65480 was recently identified as a direct transcriptional target up-regulated by WUS. We have independently which we term CCI1 interacting...

Proper control of stem cell populations is key for the development all multicellular organisms. In Arabidopsis, cells are located primarily in shoot, root and floral meristems where they undergo complex regulation. The Arabidopsis shoot regulated by related WUS WOX5 pathways, respectively. Previous studies established that these pathways share signal transduction components POLTERGEIST (POL) PLL1. Our latest study Plant Cell revealed roles acyl modifications lipid binding regulation two type...