Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Formins”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed2006

An unusual Zn-finger/FH2 domain protein controls a left/right asymmetric neuronal fate decision in C. elegans.

Gene regulatory networks that control the terminally differentiated state of a cell are, by and large, only superficially understood. In a mutant screen aimed at identifying regulators of gene batteries that define the differentiated state of two left/right asymmetric C. elegans gustatory neurons, ASEL and ASER, we have isolated a mutant, fozi-1, with a novel mixed-fate phenotype, characterized by de-repression of ASEL fate in ASER. fozi-1 codes for a protein that functions in the nucleus of ASER to inhibit the expression of the LIM homeobox gene lim-6, neuropeptide-encoding genes and putative chemoreceptors of the GCY gene family. The FOZI-1 protein displays a highly unusual domain architecture, that combines two functionally essential C2H2 zinc-finger domains, which are probably involved in transcriptional regulation, with a formin homology 2 (FH2) domain, normally found only in cytosolic regulators of the actin cytoskeleton. We demonstrate that the FH2 domain of FOZI-1 has lost its actin polymerization function but maintains its phylogenetically ancient ability to homodimerize. fozi-1 genetically interacts with several transcription factors and micro RNAs in the context of specific regulatory network motifs. These network motifs endow the system with properties that provide insights into how cells adopt their stable terminally differentiated states.

Alleles↗
PubMed2006

Profilin is an effector for Daam1 in non-canonical Wnt signaling and is required for vertebrate gastrulation.

Non-canonical Wnt signaling plays important roles during vertebrate embryogenesis and is required for cell motility during gastrulation. However, the molecular mechanisms of how Wnt signaling regulates modification of the actin cytoskeleton remain incompletely understood. We had previously identified the Formin homology protein Daam1 as an important link between Dishevelled and the Rho GTPase for cytoskeletal modulation. Here, we report that Profilin1 is an effector downstream of Daam1 required for cytoskeletal changes. Profilin1 interacted with the FH1 domain of Daam1 and was localized with Daam1 to actin stress fibers in response to Wnt signaling in mammalian cells. In addition, depletion of Profilin1 inhibited stress fiber formation induced by non-canonical Wnt signaling. Inhibition or depletion of Profilin1 in vivo specifically inhibited blastopore closure in Xenopus but did not affect convergent extension movements, tissue separation or neural fold closure. Our studies define a molecular pathway downstream of Daam1 that controls Wnt-mediated cytoskeletal reorganization for a specific morphogenetic process during vertebrate gastrulation.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Mutations in the Rho1 small GTPase disrupt morphogenesis and segmentation during early Drosophila development.

Rho GTPases play an important role in diverse biological processes such as actin cytoskeleton organization, gene transcription, cell cycle progression and adhesion. They are required during early Drosophila development for proper execution of morphogenetic movements of individual cells and groups of cells important for the formation of the embryonic body plan. We isolated loss-of-function mutations in the Drosophila Rho1 (Rho1) gene during a genetic screen for maternal-effect mutations, allowing us to investigate the specific roles Rho1 plays in the context of the developing organism. Here we report that Rho1 is required for many early events: loss of Rho1 function results in both maternal and embryonic phenotypes. Embryos homozygous for the Rho1 mutation exhibit a characteristic zygotic phenotype, which includes severe defects in head involution and imperfect dorsal closure. Two phenotypes are associated with reduction of maternal Rho1 activity: the actin cytoskeleton is disrupted in egg chambers, especially in the ring canals and embryos display patterning defects as a result of improper maintenance of segmentation gene expression. Despite showing imperfect dorsal closure, Rho1 does not activate downstream genes or interact genetically with members of the JNK signaling pathway, used by its relatives dRac and dCdc42 for proper dorsal closure. Consistent with its roles in regulating actin cytoskeletal organization, we find that Rho1 interacts genetically and physically with the Drosophila formin homologue, cappuccino. We also show that Rho1 interacts both genetically and physically with concertina, a G(alpha) protein involved in cell shape changes during gastrulation.

Actins↗
PubMed2005

Candida albicans hyphae have a Spitzenkörper that is distinct from the polarisome found in yeast and pseudohyphae.

Fungi grow with a variety of morphologies: oval yeast cells, chains of elongated cells called pseudohyphae and long, narrow, tube-like filaments called hyphae. In filamentous fungi, hyphal growth is strongly polarised to the tip and is mediated by the Spitzenkörper, which acts as a supply centre to concentrate the delivery of secretory vesicles to the tip. In the budding yeast Saccharomyces cerevisiae, polarised growth is mediated by the polarisome, a surface cap of proteins that nucleates the formation of actin cables delivering secretory vesicles to the growing tip. The human fungal pathogen, Candida albicans, can grow in all three morphological forms. Here we show the presence of a Spitzenkörper at the tip of C. albicans hyphae as a ball-like localisation of secretory vesicles, together with the formin Bni1 and Mlc1, an ortholog of an S. cerevisiae myosin regulatory light chain. In contrast, in C. albicans yeast cells, pseudohyphae and hyphae Spa2 and Bud6, orthologs of S. cerevisiae polarisome components, as well as the master morphology regulator Cdc42, localise predominantly, but not exclusively, to a surface cap resembling the polarisome of S. cerevisiae yeast cells. A small amount of Cdc42 also localises to the Spitzenkörper. Furthermore, we show differences in the genetic and cytoskeletal requirements, and cell cycle dynamics of polarity determinants in yeast, pseudohyphae and hyphae. These results, together with the cytological differences between the cell types, suggest that the Spitzenkörper and polarisome are distinct structures, that the polarisome and Spitzenkörper coexist in hyphae, and that polarised growth in hyphae is driven by a fundamentally different mechanism to that in yeast and pseudohyphae.

Candida albicans↗
PubMed2005

Endocytosis in fission yeast is spatially associated with the actin cytoskeleton during polarised cell growth and cytokinesis.

In the fission yeast, Schizosaccharomyces pombe, uptake of the fluorescent styryl dye FM4-64 via the endocytic pathway to the vacuole was localised to the poles of growing, interphase cells and to the cell equator during cell division, regions of cell wall deposition that are rich in actin. When the pattern of growth or the plane of cytokinesis was altered, the relationship between the actin cytoskeleton and the site of endocytosis was maintained. Transfer of the label to the vacuolar membrane was dependent upon the Rab GTPase Ypt7 and, hence, vesicle fusion. Endocytic vesicles transiently colocalised with actin patches and endocytosis was inhibited in mutants that affected actin patch integrity and by the actin inhibitor latrunculin A. Concentrations of latrunculin that removed actin cables but left patches unaffected had no effect on endocytosis at the poles, but abolished endocytosis at the cell equator. Equatorial, but not polar, endocytosis was also inhibited in cells lacking the formin For3 (which have selectively destabilised actin cables), in mutants of the exocyst complex and in cells treated with brefeldin A. Differential effects on endocytosis at the cell poles and equator were also observed in the actin mutant cps8 and the Arp2/3 complex mutant arp2. The redirection of endocytosis from the cell poles to the cell equator in M phase coincided with the anaphase separation of sister chromatids and was abolished in the septation initiation network (SIN) mutants cdc7, sid1 and sid2, demonstrating that the spatial reorganisation of the endocytic pathway in the S. pombe cell cycle requires a functional SIN pathway. We conclude that endocytosis in fission yeast has two distinct components, both of which are actin-based, but which are mechanistically distinct, as well as being spatially and temporally separated in the S. pombe cell cycle.

Actins↗
PubMed2007

Reciprocal regulation of Rac1 and Rho1 in Drosophila circulating immune surveillance cells.

In many cell types it is evident that the small GTPases Rac and Rho regulate each other's activities. What is unclear is exactly how this regulation occurs. To further elucidate this interaction we examined the activities of Rac1 and Rho1 in Drosophila cellular immune surveillance cells. In larvae the cellular immune response involves circulating cells (hemocytes) that can be recruited from a hematopoietic organ located behind the brain, as well as a sessile population found just underneath the larval cuticle. We demonstrate for the first time that Rho-kinase activation requires both Rho1 and the Drosophila c-Jun N-terminal kinase (Basket). We also show that Rac1, via Basket, regulates Rho1 activity, possibly by inhibiting RhoGAPp190. In the reciprocal pathway, co-expression of dominant negative Rho-kinase and constitutive active Rho1 induces a Rac1-like phenotype. This induction requires the formin Diaphanous. Co-expression of dominant negative Rho-kinase and constitutive active Rho1 also induces filopodia formation, with Diaphanous enriched at the tips. The Rac1-like phenotypes, and filopodia formation, could be blocked by co-expression of dominant negative Rac1. Finally, though dominant negative Rac1 is able to block filopodia formation in the overexpression experiments, only Rac2 is necessary for filopodia formed by hemocytes after parasitization.

Animals↗
PubMed1998

F-actin distribution and function during sexual differentiation in Schizosaccharomyces pombe.

Sexual differentiation in Schizosaccharomyces pombe is induced from the G1 phase of the cell cycle by nitrogen starvation and the presence of mating pheromones. We describe the distribution of F-actin during sexual differentiation. Cortical F-actin dots have previously been shown to be restricted to one end of the rod shaped cell during the G1 phase of the cell cycle. Within half an hour of nitrogen starvation the distribution of cortical F-actin dots switched from being monopolar to bipolar. This was then reversed as the F-actin cytoskeleton repolarized so that cortical F-actin dots accumulated towards the projection tip at one end of the cell. Following cell fusion, F-actin dots were randomly scattered during the horsetail movement that precedes meiosis I and remained scattered until prometaphase or metaphase of meiosis II, when they concentrated around the nucleus. F-actin was seen on the lagging face of the nuclei which faced the partner nucleus during anaphase B of meiosis II. Early on in this anaphase F-actin was also seen on the opposite side of the nucleus, near the spindle pole body. F-actin accumulated within the spores in the mature ascus. Treatment with the actin depolymerising drug Latrunculin A showed that F-actin is required for cell fusion and spore formation. Latrunculin A treatment extended all stages from karyogamy to meiosis I. The S. pombe homologue of the actin binding protein profilin, Cdc3, was shown to be required for conjugation. Cdc3 co-localized with the formin related molecule Fus1 at the projection tip. The polarization of F-actin cortical dots to the projection tip was unaffected in the cdc3.124 mutant, but cdc3.124 mutant cells were unable to break down the cell walls between the two cells following agglutination.

Actin Cytoskeleton↗
PubMed2006

Folding, misfolding, and amyloid protofibril formation of WW domain FBP28.

We study the folding mechanism of a triple beta-strand WW domain from the Formin binding protein 28 (FBP28) at atomic resolution with explicit water model using replica exchange molecular dynamics computer simulations. Extended sampling over a wide range of temperatures to obtain the free energy, enthalpy, and entropy surfaces as a function of structural coordinates has been performed. Simulations were started from different configurations covering the folded and unfolded states. In the free energy landscape a transition state is identified and its structures and -values are compared with experimental data from a homologous protein, the prolyl-isomerase Pin1 WW domain. A stable intermediate state is found to accumulate during the simulation characterized by the carboxyl-terminal beta-strand 3 having misregistered hydrogen bonds and where the structural heterogeneity is due to nonnative turn II formation. Furthermore, the aggregation behavior of the FBP28 WW domain may be related to one such misfolded structure, which has a much lower free energy of dimer formation than that of the native dimer. Based on the misfolded dimer, aggregation to form protofibril structure is discussed.

Amyloid↗
PubMed2007

Attachment conditions control actin filament buckling and the production of forces.

Actin polymerization is the driving force for a large number of cellular processes. Formation of lamellipodia and filopodia at the leading edge of motile cells requires actin polymerization induced mechanical deformation of the plasma membrane. To generate different types of membrane protrusions, the mechanical properties of actin filaments can be constrained by interacting proteins. A striking example of such constraint is the buckling of actin filaments generated in vitro by the cooperative effect of a processive actin nucleating factor (formin) and a molecular motor (myosin II). We developed a physical model based on equations for an elastic rod that accounts for actin filament buckling. Both ends of the rod were maintained in a fixed position in space and we considered three sets of boundary conditions. The model qualitatively and quantitatively reproduces the shape distribution of actin filaments. We found that actin polymerization counterpoises a force in the range 0.4-1.6 pN for moderate end-to-end distance (approximately 1 microm) and could be as large as 10 pN for shorter distances. If the actin rod attachment includes a spring, we discovered that the stiffness must be in the range 0.1-1.2 pN/nm to account for the observed buckling.

Actin Cytoskeleton↗
PubMed2004

Fus1p interacts with components of the Hog1p mitogen-activated protein kinase and Cdc42p morphogenesis signaling pathways to control cell fusion during yeast mating.

Cell fusion in the budding yeast Saccharomyces cerevisiae is a temporally and spatially regulated process that involves degradation of the septum, which is composed of cell wall material, and occurs between conjugating cells within a prezygote, followed by plasma membrane fusion. The plasma membrane protein Fus1p is known to be required for septum degradation during cell fusion, yet its role at the molecular level is not understood. We identified Sho1p, an osmosensor for the HOG MAPK pathway, as a binding partner for Fus1 in a two-hybrid screen. The Sho1p-Fus1p interaction occurs directly and is mediated through the Sho1p-SH3 domain and a proline-rich peptide ligand on the Fus1p COOH-terminal cytoplasmic region. The cell fusion defect associated with fus1Delta mutants is suppressed by a sho1Delta deletion allele, suggesting that Fus1p negatively regulates Sho1p signaling to ensure efficient cell fusion. A two-hybrid matrix containing fusion proteins and pheromone response pathway signaling molecules reveals that Fus1p may participate in a complex network of interactions. In particular, the Fus1p cytoplasmic domain interacts with Chs5p, a protein required for secretion of specialized Chs3p-containing vesicles during bud development, and chs5Delta mutants were defective in cell surface localization of Fus1p. The Fus1p cytoplasmic domain also interacts with the activated GTP-bound form of Cdc42p and the Fus1p-SH3 domain interacts with Bni1p, a yeast formin that participates in cell fusion and controls the assembly of actin cables to polarize secretion in response to Cdc42p signaling. Taken together, our results suggest that Fus1p acts as a scaffold for the assembly of a cell surface complex involved in polarized secretion of septum-degrading enzymes and inhibition of HOG pathway signaling to promote cell fusion.

Fungal Proteins↗
PubMedDate not supplied

Metformin-induced cholestatic hepatitis.

OBJECTIVE: To report a case of metformin-induced cholestatic hepatitis. METHODS: We present a detailed case report, including laboratory and biopsy findings. In addition, similar cases from the literature are reviewed. RESULTS: In a 68-year-old man with newly diagnosed diabetes mellitus, metformin therapy was begun. The dosage initially was 500 mg twice daily and later was increased to 850 mg twice a day. Four weeks after met-formin treatment was initiated, jaundice, pruritus, and liver enzyme abnormalities were noted. The patient underwent an extensive work-up, including a hepatitis screen, ultrasonography, magnetic resonance imaging, and endoscopic retrograde cholangiopancreatography, all of which showed normal findings. A liver biopsy revealed severe cholestasis and mild portal inflammation. Treatment with metformin was discontinued, and the liver enzymes normalized except for a persistently increased level of alkaline phosphatase, most likely related to a prolonged cholestatic effect of metformin. CONCLUSION: Although rare, metformin can be responsible for inducing liver damage, and patients and physicians should be aware of this side effect.

Aged↗
PubMed2006

Identification of genes downregulated in tumor cells expressing antisense glutaminase mRNA by differential display.

Ehrlich ascites tumor cells (EATC) is a highly proliferative malignant cell line derived from mouse mammary epithelia, whereas their derivative, 0.28AS-2 cells, expressing antisense glutaminase mRNA, show a less transformed phenotype and loss of their tumorigenic capacity in vivo correlated with an inhibition of glutaminase expression. The mRNA differential display technique was applied to these two cell lines for the identification and isolation of genes whose transcription was altered. Side-by-side comparisons of cDNA patterns among relevant RNA samples revealed four genes significantly downregulated in 0.28AS-2 cells: high-mobility group Hmga2 protein, Fmnl3 or formin-like protein 3, Nedd-4 ubiquitin-protein ligase, and ubiquitin carboxyl-terminal hydrolase Usp-15. These positives were confirmed by Northern analysis. The four targeted genes have relevant functions in cell growth and proliferation. Our results show the validity of mRNA differential display technique to get insights into the molecular mechanisms underlying the acquisition of a more differentiated phenotype by tumor cells after inhibition of glutaminase expression.

Animals↗
PubMed1999

Oxalate: from crystal formation to crystal retention.

Idiopathic calcium oxalate stone formation is a multifactorial disease. It is therefore unlikely that a single underlying condition will be responsible for entire spectrum of the disease; however, it appears that one important factor in the pathogenesis is an abnormality in oxalate metabolism. Whatever the cause, two critical parameters for stone formation are crystal formation and crystal retention in the renal tubules. Although crystal formination and role of oxalate in crystal formation have been evaluated extensively, it is only recently that crystal retention has been addressed. Previous studies from our laboratories demonstrated that oxalate exposure to renal epithelial cells in culture resulted in initiation of a program of events including DNA synthesis and cell death. The present studies evaluated effects of oxalate on cell proliferation and damage to distal tubular (Madin-Darby canine kidney cells) and proximal (LLC-PK1 cells) cells. Effects of oxalate exposure on calcium oxalate monohydrate (COM) crystal adherence to these cells were also evaluated. Results presented herein demonstrate that proximal tubular cells are more sensitive to oxalate than distal tubular cells. Furthermore, oxalate exposure to proximal tubular cells resulted in reinitiation of DNA synthesis, whereas no such effect was observed in distal tubular cells. Higher levels of oxalate (> 1 mM) resulted in cell loss of both proximal and distal tubular cells, as observed by crystal violet staining. Despite these differences, oxalate exposure to both proximal and distal tubular cells resulted in increased COM crystal adherence. Thus, oxalate exposure may promote crystal adherence to renal epithelial cells either secondarily to cell death and proliferation or by a yet unidentified mechanism. These studies provide the first direct evidence for the role of oxalate in promoting COM crystal retention by the urothelium.

Animals↗
PubMed2003

FNBP2 gene on human chromosome 1q32.1 encodes ARHGAP family protein with FCH, FBH, RhoGAP and SH3 domains.

Parallel analyses of DNA copy number and mRNA expression level by using microarray measurements have been successfully applied for genome-wide screening of proto-oncogenes and tumor suppressor genes. The uncharacterized KIAA0456 cDNA was reported amplified and overexpressed in human breast cancer cell lines UACC812 and ZR-75-1. Here, we characterized the gene corresponding to KIAA0456 cDNA by using bioinformatics. KIAA0456 cDNA was found derived from the FNBP2 gene, consisting of 22 exons. FNBP2 gene was linked to IKBKE and NORE1 genes on human chromosome 1q32.1. FNBP2 mRNA was expressed in melanoma, germ cell tumors, chondrosarcoma and retinoblastoma. ARHGAP13/SRGAP1, ARHGAP14/SRGAP2 and ARHGAP4 cDNAs were homologous to FNBP2/KIAA0456 cDNA. KIAA1304 cDNA was a splicing variant derived from the ARHGAP13 gene, and the nucleotide sequence of representative ARHGAP13 cDNA was determined by assembling EST BU520980 and KIAA1304 cDNA. FNBP2 (1071 aa), ARHGAP13 (1062 aa), ARHGAP14 (1099 aa) and ARHGAP4 (946 aa) constitute the FNBP2 family characterized by FCH, RhoGAP and SH3 domains. The region corresponding to codon 227-345 of FNBP2 was conserved among FNBP2 family proteins as well as FNBP1 and TRIP10 proteins. Because FNBP2 and FNBP1 are formin-binding proteins, the region corresponding to codon 227-345 of FNBP2 was designated FNBP2-FNBP1 homologous (FBH) domain. FNBP2 family proteins consist of FCH, FBH, RhoGAP and SH3 domains, while FNBP1 family proteins (FNBP1 and TRIP10) consist of FCH, FBH and SH3 domains. This is the first report on comprehensive characterization of FNBP2 gene as well as on identification of the FBH domain.

Adaptor Proteins, Signal Transducing↗
PubMed2003

A proline-rich domain in the gamma subunit of phosphodiesterase 6 mediates interaction with SH3-containing proteins.

PURPOSE: Phosphodiesterase 6 (PDE6) is the primary effector of phototransduction in vertebrate photoreceptors. Previous studies described the expression of the regulatory subunit of rod PDE6 (Pgamma-rod) in non-photosensitive tissues of the adult rat and the effects of this protein on MAP kinase pathways. Upon examination of the Pgamma-rod sequence, we detected a proline-rich domain that might reveal its ability to interact with SH3-containing proteins. Therefore, the present study was initiated to identify new protein partners of Pgamma-rod. METHODS: A yeast two-hybrid screen of a rat brain cDNA library was performed using Pgamma-rod as a bait. Pgamma-rod-SH3 interaction was confirmed by GST pull-down of in vitro-translated proteins. The aminoacids involved in the interaction were mapped by site-directed mutagenesis. Rnase protection assay, RT-PCR and western blot analysis were used to detect Pgamma-rod expression in various rat tissues. RESULTS: A clone was isolated twice, that consisted essentially of the SH3 domain of the formin-binding protein 17 (FBP17). This interaction was confirmed by GST pull-down. Mutational analysis of the Pgamma-rod-FBP17 interaction confirmed it involved the proline-rich domain of Pgamma-rod and the SH3 domain of FBP17. This proline-rich domain also allowed Pgamma-rod to interact with Cdc42-interacting protein 4 (CIP4), another SH3-containing protein. RT-PCR and Rnase protection assay detected different amounts of Pgamma-rod mRNA in adult and embryonic rat tissues. Western blots confirmed the presence of low levels of Pgamma-rod protein only in embryonic tissues. CONCLUSIONS: Our data suggest that Pgamma-rod participates in SH3-mediated cellular pathways and may therefore play a wider role than previously appreciated. One possibility is that FBP17 interaction with sorting nexin 2 might connect Pgamma-rod to receptor tyrosine kinase recycling. However, further studies are still required to identify the diversity of SH3-containing proteins that interact with Pgamma-rod. This effort should provide a rationale to understand how Pgamma-rod can affect receptor internalization-dependent MAP kinase activity.

Amino Acid Sequence↗
PubMed2004

Identification and characterization of human FCHSD1 and FCHSD2 genes in silico.

FNBP1 and FNBP2 are SH3-type Formin-binding proteins. FNBP1 consists of FCH, FBH, HR1 and SH3 domains, while FNBP2 consists of FCH, FBH, RhoGAP and SH3 domains. Here, we identified novel genes FCHSD1 and FCHSD2, which were distantly related to FNBP1 and FNBP2. FCHSD1 and FCHSD2 genes with conserved exon-intron structure were located at human chromosome 5q31.3 and 11q13.4, respectively. Complete coding sequence of human FCHSD1 was derived from FLJ00007 (NM_033449.1) cDNA. KIAA0769 (NM_014824.1), encoding N-terminally truncated 684-aa protein, was an aberrant human FCHSD2 cDNA with a frame shift due to skipping of 98-bp exon 2. Complete coding sequence of human FCHSD2 cDNA was determined by assembling CF995054 EST and KIAA0769 cDNA. A030002D08Rik (NM_175684.3) was the representative mouse Fchsd1 cDNA, while BC034086 (NM_199012.1) was a variant mouse Fchsd2 cDNA with an insertion of 72-bp additional exon. CG4684 was the Drosophila homolog of mammalian FCHSD family genes. Human FCHSD1 (690 aa) showed 41.7% total-amino-acid identity with human FCHSD2 (740 aa), and 91.0% total-amino-acid identity with mouse Fchsd1. Human FCHSD2 showed 96.5% total-amino-acid identity with mouse Fchsd2. Mammalian FCHSD family proteins shared the common domain structure consisting of FCH, FBH, two SH3 and C-terminal Proline-rich domains. FCHSD family proteins (FCHSD1 and FCHSD2), FNBP1 family proteins (FNBP1, FNBP1L and TRIP10/CIP4) and FNBP2 family proteins (FNBP2, ARHGAP13/SRGAP1, ARHGAP14/SRGAP2 and ARHGAP4) were found constituting the FCFBS superfamily characterized by FCH, FBH and SH3 domains. This is the first report on identification and characterization of the FCHSD family genes.

Amino Acid Sequence↗
PubMed2004

Identification and characterization of human FCHO2 and mouse Fcho2 genes in silico.

FNBP1, FNBP1L, CIP4/TRIP10, FNBP2, SRGAP1/ARHGAP13, SRGAP2/ARHGAP14, ARHGAP4, FCHSD1, and FCHSD2 constitute the FCFBS superfamily characterized by FES-CIP4 homology (FCH) domain, Formin-binding FNBP1-FNBP2 homology (FBH) domain, and SRC homology 3 (SH3) domain. During genome-wide searching for human genes encoding FCH domain molecules, we identified the FCHO2 gene by using bioinformatics. DKFZp451B033 (AL831971.1) was the representative cDNA derived from human FCHO2 gene, while FLJ32208 (AK056770.1) was a chimeric cDNA generated by the recombination between FCHO2 and CSH1 genes. MGC63242 (BC052456.1) rather than 5832424M12 (AK031041.1) was the representative cDNA derived from mouse Fcho2 gene. FCHO2 gene, consisting of 26 exons, was mapped to human chromosome 5q13.2. Human FCHO2 (810 aa) showed 94.6% total-amino-acid identity with mouse Fcho2 (809 aa), and 50.4% total-amino-acid identity with human FCHO1. Drosophila CG8176 (NP_788613.1) and C. elegans 2B609 (NP_493947.1) were homologs of mammalian FCHO2 and FCHO1. FCHO-homologous (FOH) domain (codon 527-810 of human FCHO2) was identified as the novel domain conserved among FCHO homologs. Human FCHO2, FCHO1, Drosophila CG8176 and C. elegans 2B609 were found consisting of N-terminal FCH domain and C-terminal FOH domain. This is the first report on identification and characterization of evolutionarily conserved FCHO homologs as well as the novel FOH domain.

Amino Acid Sequence↗
PubMed2004

Identification and characterization of CDC50A, CDC50B and CDC50C genes in silico.

Bni1p, implicated in cell polarity control and microtubule regulation during yeast budding, is the Saccharomyces cerevisiae homolog of human Formin-homology proteins, such as FMN1, FMN2, FHOD1, FHOD3, FHDC1, GRID2IP, FMNL1, FMNL2, FMNL3, DIAPH1, DIAPH2, DIAPH3, DAAM1 and DAAM2. Cdc50p is necessary for subcellular localization of Bni1p and asymmetrical cell division. Lem3p and Ynr048wp are yeast homologs of Cdc50p; however, mammalian homologs of Cdc50p remained to be identified. Here, we identified and characterized CDC50A (TMEM30A), CDC50B (TMEM30B) and CDC50C (TMEM30C) genes by using bioinformatics. C6orf67 and FLJ33850 were representative human CDC50A and CDC50B cDNAs, respectively. Complete coding sequence of CDC50C cDNA was determined by assembling seven exons within AC129803.3 genome sequence. CDC50A, CDC50B and CDC50C genes were mapped to human chromosome 6q14.1, 14q23.1 and 3q12, respectively. Human CDC50A mRNA was expressed in embryonic stem (ES) cells, placenta, brain and chondrosarcoma, while CDC50B mRNA was expressed in pancreatic islet, kidney, prostate as well as in lung carcinoid, parathyroid tumor, bladder tumor, meningioma and pancreatic cancer. Mouse Cdc50a (2010200I23), Cdc50b (9130011B11) and Cdc50c (4933401B01) cDNAs were also identified. Mammalian CDC50 homologs, including human CDC50A (361 aa), CDC50B (351 aa), CDC50C (341 aa), mouse Cdc50a (364 aa), Cdc50b (353 aa) and Cdc50c (342 aa), were two-transmembrane-spanning proteins with one extracellular loop. Membrane topology and extracellular loop containing three Cys residues and one Asn-linked glycosylation site were evolutionarily conserved among mammalian CDC50 homologs and yeast Cdc50p homologs. Mammalian CDC50 homologs were predicted components of phospholipid-translocators just like yeast Cdc50p and Lem3p.

Adaptor Proteins, Signal Transducing↗