Abstract:
:Formins have conserved roles in cell polarity and cytokinesis and directly nucleate actin filament assembly through their FH2 domain. Here, we define the active region of the yeast formin Bni1 FH2 domain and show that it dimerizes. Mutations that disrupt dimerization abolish actin assembly activity, suggesting that dimers are the active state of FH2 domains. The Bni1 FH2 domain protects growing barbed ends of actin filaments from vast excesses of capping protein, suggesting that the dimer maintains a persistent association during elongation. This is not a species-specific mechanism, as the activities of purified mammalian formin mDia1 are identical to those of Bni1. Further, mDia1 partially complements BNI1 function in vivo, and expression of a dominant active mDia1 construct in yeast causes similar phenotypes to dominant active Bni1 constructs. In addition, we purified the Bni1-interacting half of the cell polarity factor Bud6 and found that it binds specifically to actin monomers and, like profilin, promotes rapid nucleotide exchange on actin. Bud6 and profilin show additive stimulatory effects on Bni1 activity and have a synthetic lethal genetic interaction in vivo. From these results, we propose a model in which Bni1 FH2 dimers nucleate and processively cap the elongating barbed end of the actin filament, and Bud6 and profilin generate a local flux of ATP-actin monomers to promote actin assembly.
journal_name
Mol Biol Celljournal_title
Molecular biology of the cellauthors
Moseley JB,Sagot I,Manning AL,Xu Y,Eck MJ,Pellman D,Goode BLdoi
10.1091/mbc.e03-08-0621keywords:
subject
Has Abstractpub_date
2004-02-01 00:00:00pages
896-907issue
2eissn
1059-1524issn
1939-4586pii
E03-08-0621journal_volume
15pub_type
杂志文章abstract::We recently identified transmembrane protein shrew-1 and showed that it is able to target to adherens junctions in polarized epithelial cells. This suggested shrew-1 possesses specific basolateral sorting motifs, which we analyzed by mutational analysis. Systematic mutation of amino acids in putative sorting signals i...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e05-11-1034
更新日期:2006-08-01 00:00:00
abstract::Dynamic regulation of cytoskeletal contractility through phosphorylation of the nonmuscle Myosin-II regulatory light chain (MRLC) provides an essential source of tension for shaping epithelial tissues. Rho GTPase and its effector kinase ROCK have been implicated in regulating MRLC phosphorylation in vivo, but evidence...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E10-04-0328
更新日期:2010-08-15 00:00:00
abstract::The target of rapamycin kinase complex 1 (TORC1) regulates cell growth and metabolism in eukaryotes. In Saccharomyces cerevisiae, TORC1 activity is known to be controlled by the conserved GTPases, Gtr1/2, and movement into and out of an inactive agglomerate/body. However, it is unclear whether/how these regulatory ste...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E18-05-0297
更新日期:2019-02-01 00:00:00
abstract::During differentiation, keratinocytes undergo a dramatic shape change from small and round to large and flat, in addition to production of proteins necessary for the formation of epidermis. It has been shown that protein kinase C (PKC) η is crucial for keratinocyte differentiation. However, its role in this process ha...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E10-09-0754
更新日期:2011-04-15 00:00:00
abstract::Myosin Va is associated with discrete vesicle populations in a number of cell types, but little is known of the function of myosin Vb. Yeast two-hybrid screening of a rabbit parietal cell cDNA library with dominant active Rab11a (Rab11aS20V) identified myosin Vb as an interacting protein for Rab11a, a marker for plasm...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.12.6.1843
更新日期:2001-06-01 00:00:00
abstract::An in vitro transport assay, established with a modified Shiga toxin B subunit (STxB) as a marker, has proved to be useful for the study of transport from the early/recycling endosome (EE/RE) to the trans-Golgi network (TGN). Here, we modified this assay to test antibodies to all known soluble N-ethylmaleimide-sensiti...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e03-12-0876
更新日期:2004-09-01 00:00:00
abstract::Cell morphogenesis depends on polarized exocytosis. One widely held model posits that long-range transport and exocyst-dependent tethering of exocytic vesicles at the plasma membrane sequentially drive this process. Here, we describe that disruption of either actin-based long-range transport and microtubules or the ex...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E10-08-0720
更新日期:2011-01-01 00:00:00
abstract::Syntaxin 3 (Stx3), a SNARE protein located and functioning at the apical plasma membrane of epithelial cells, is required for epithelial polarity. A fraction of Stx3 is localized to late endosomes/lysosomes, although how it traffics there and its function in these organelles is unknown. Here we report that Stx3 underg...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E17-07-0461
更新日期:2017-10-15 00:00:00
abstract::Polarized cell growth requires the coupling of a defined spatial site on the cell cortex to the apparatus that directs the establishment of cell polarity. In the budding yeast Saccharomyces cerevisiae, the Ras-family GTPase Rsr1p/Bud1p and its regulators select the proper site for bud emergence on the cell cortex. The...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e03-06-0426
更新日期:2003-12-01 00:00:00
abstract::Repellents evoke growth cone turning by eliciting asymmetric, localized loss of actin cytoskeleton together with changes in substratum attachment. We have demonstrated that semaphorin-3A (Sema3A)-induced growth cone detachment and collapse require eicosanoid-mediated activation of protein kinase C epsilon (PKC epsilon...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e05-12-1183
更新日期:2006-12-01 00:00:00
abstract::Targeting of peroxisomal membrane proteins (PMPs) is a multistep process that requires not only recognition of PMPs in the cytosol but also their insertion into the peroxisomal membrane. As a consequence, targeting signals of PMPs (mPTS) are rather complex. A candidate protein for the PMP recognition event is Pex19p, ...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e04-03-0188
更新日期:2004-07-01 00:00:00
abstract::Cysteine string protein (Csp) is essential for neurotransmitter release in Drosophila. It has been suggested that Csp functions by regulating the activity of presynaptic Ca2+ channels, thus controlling exocytosis. We have examined the effect of overexpressing Csp1 in PC12 cells, a neuroendocrine cell line. PC12 cell c...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.9.8.2259
更新日期:1998-08-01 00:00:00
abstract::Cystic fibrosis (CF) is a fatal genetic disorder associated with defective hydration of lung airways due to the loss of chloride transport through the CF transmembrane conductance regulator protein (CFTR). CFTR contains two membrane-spanning domains (MSDs), two nucleotide-binding domains (NBDs), and a regulatory domai...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E13-05-0240
更新日期:2013-10-01 00:00:00
abstract::Stimulation of the T-cell receptor (TCR) results in the activation of several transcription factors, including NF-kappaB, that are crucial for T-cell proliferation and gain of effector functions. On TCR engagement, several proteins within the TCR-directed NF-kappaB signaling pathway undergo dynamic spatial redistribut...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e05-10-0985
更新日期:2006-05-01 00:00:00
abstract::Werner syndrome (WS) is a human progeroid syndrome characterized by the early onset of a large number of clinical features associated with the normal aging process. The complex molecular and cellular phenotypes of WS involve characteristic features of genomic instability and accelerated replicative senescence. The gen...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.10.8.2655
更新日期:1999-08-01 00:00:00
abstract::Doing scientific research can be a challenging, but creative and rewarding career. However, the challenge of doing research is orders of magnitude more difficult for scientists lacking access to the necessary resources. Resource-scarce environments are quite common worldwide and are highly contingent on the financial ...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E17-11-0645
更新日期:2018-06-01 00:00:00
abstract::Actin-based protrusions are important for signaling and migration during development and homeostasis. Defining how different tissues in vivo craft diverse protrusive behaviors using the same genomic toolkit of actin regulators is a current challenge. The actin elongation factors Diaphanous and Enabled both promote bar...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E14-05-0951
更新日期:2014-10-15 00:00:00
abstract::Keratins are cytoplasmic intermediate filament proteins preferentially expressed by epithelial tissues in a site-specific and differentiation-dependent manner. The complex network of keratin filaments in stratified epithelia is tightly regulated during squamous cell differentiation. Keratin 14 (K14) is expressed in mi...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E10-08-0703
更新日期:2011-11-01 00:00:00
abstract::Stress fibers were isolated from cultured human foreskin fibroblasts and bovine endothelial cells, and their contraction was demonstrated in vitro. Cells in culture dishes were first treated with a low-ionic-strength extraction solution and then further extracted using detergents. With gentle washes by pipetting, the ...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.9.7.1919
更新日期:1998-07-01 00:00:00
abstract::Proteins establish and maintain a distinct intracellular localization by means of targeting, retention, and retrieval signals, ensuring most proteins reside predominantly in one cellular location. The enzymes involved in the maturation of lamin A present a challenge to this paradigm. Lamin A is first synthesized as a ...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e08-07-0704
更新日期:2008-12-01 00:00:00
abstract::As yeast cultures enter stationary phase in rich, glucose-based medium, differentiation of two major subpopulations of cells, termed quiescent and nonquiescent, is observed. Differences in mRNA abundance between exponentially growing and stationary-phase cultures and quiescent and nonquiescent cells are known, but lit...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E10-06-0499
更新日期:2011-04-01 00:00:00
abstract::Most mitochondrial proteins are synthesized as precursors that carry N-terminal presequences. After they are imported into mitochondria, these targeting signals are cleaved off by the mitochondrial processing peptidase (MPP). Using the mitochondrial tandem protein Arg5,6 as a model substrate, we demonstrate that MPP h...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E20-08-0524
更新日期:2020-11-15 00:00:00
abstract::Septins are conserved GTP-binding cytoskeletal proteins that polymerize into filaments by end-to-end joining of hetero-oligomeric complexes. In human cells, both hexamers and octamers exist, and crystallography studies predicted the order of the hexamers to be SEPT7-SEPT6-SEPT2-SEPT2-SEPT6-SEPT7, while octamers are th...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E20-06-0398
更新日期:2021-02-01 00:00:00
abstract::Activation of the inflammatory response is accompanied by a metabolic shift to aerobic glycolysis. Here we identify histone deacetylase 4 (HDAC4) as a new component of the immunometabolic program. We show that HDAC4 is required for efficient inflammatory cytokine production activated by lipopolysaccharide (LPS). Surpr...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E13-12-0757
更新日期:2014-11-01 00:00:00
abstract::Secretory proteins are exported from the endoplasmic reticulum in COPII vesicles. SNARE proteins-core machinery for membrane fusion-are incorporated into COPII vesicles by direct interaction with Sec24. Here we report a novel mechanism for sorting of the ER-Golgi Q-SNAREs into COPII vesicles. Different mammalian Sec24...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.E16-04-0229
更新日期:2016-09-01 00:00:00
abstract::Functionally different subsets of actin filament arrays contribute to cellular organization and motility. We report the identification of a novel subset of loose actin filament arrays through regulated association with the widely expressed protein SWAP-70. These loose actin filament arrays were commonly located behind...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e03-01-0043
更新日期:2003-08-01 00:00:00
abstract::Myo4p, a single-headed and nonprocessive class V myosin in budding yeast, transports >20 different mRNAs asymmetrically to the bud. Here, we determine the features of the Myo4p motor that are necessary for correct localization of ASH1 mRNA to the daughter cell, a process that also requires the adapter protein She3p an...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e08-08-0801
更新日期:2009-07-01 00:00:00
abstract::A central question in the area of signal transduction is why pathways utilize common components. In the budding yeast Saccharomyces cerevisiae, the HOG and filamentous growth (FG) MAPK pathways require overlapping components but are thought to be induced by different stimuli and specify distinct outputs. To better und...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.e08-07-0760
更新日期:2009-07-01 00:00:00
abstract::Nuclear factor kappa B (NF-kappa B) modulates the expression of numerous genes via interaction with a specific DNA sequence termed the kappa B site. Its activity is modulated by a cytosolic inhibitor protein termed I kappa B, and its activation occurs in response to a variety of agents in a variety of cell types, most...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.3.10.1131
更新日期:1992-10-01 00:00:00
abstract::CD98, an early marker of T-cell activation, is an important regulator of integrin-mediated adhesion events. Previous studies suggest that CD98 is coupled to both cellular activation and transformation and is involved in the pathogenesis of viral infection, inflammatory disease, and cancer. Understanding of the molecul...
journal_title:Molecular biology of the cell
pub_type: 杂志文章
doi:10.1091/mbc.01-11-0530
更新日期:2002-08-01 00:00:00