Kermit, a frizzled interacting protein, regulates frizzled 3 signaling in neural crest development

Development ◽  
2001 ◽  
Vol 128 (19) ◽  
pp. 3665-3674 ◽  
Author(s):  
Change Tan ◽  
Matthew A. Deardorff ◽  
Jean-Pierre Saint-Jeannet ◽  
Jing Yang ◽  
Arpine Arzoumanian ◽  
...  

Wnts are a family of secreted glycoproteins that are important for multiple steps in early development. Accumulating evidence suggests that frizzled genes encode receptors for Wnts. However, the mechanism through which frizzleds transduce a signal and the immediate downstream components that convey that signal are unclear. We have identified a new protein, Kermit, that interacts specifically with the C-terminus of Xenopus frizzled-3 (Xfz3). Kermit is a 331 amino acid protein with a central PDZ domain. Kermit mRNA is expressed throughout Xenopus development and is localized to neural tissue in a pattern that overlaps Xfz3 expression temporally and spatially. Co-expression of Xfz3 and Kermit results in a dramatic translocation of Kermit to the plasma membrane. Inhibition of Kermit function with morpholino antisense oligonucleotides directed against the 5′ untranslated region of Kermit mRNA blocks neural crest induction by Xfz3, and this is rescued by co-injection of mRNA encoding the Kermit open reading frame. These observations suggest that Kermit is required for Wnt/frizzled signaling in neural crest development. To the best of our knowledge, Kermit is the first protein identified that interacts directly with the cytoplasmic portion of frizzleds to modulate their signaling activity.

Development ◽  
2001 ◽  
Vol 128 (8) ◽  
pp. 1467-1479 ◽  
Author(s):  
R. Kos ◽  
M.V. Reedy ◽  
R.L. Johnson ◽  
C.A. Erickson

The winged-helix or forkhead class of transcription factors has been shown to play important roles in cell specification and lineage segregation. We have cloned the chicken homolog of FoxD3, a member of the winged-helix class of transcription factors, and analyzed its expression. Based on its expression in the dorsal neural tube and in all neural crest lineages except the late-emigrating melanoblasts, we predicted that FoxD3 might be important in the segregation of the neural crest lineage from the neural epithelium, and for repressing melanogenesis in early-migrating neural crest cells. Misexpression of FoxD3 by electroporation in the lateral neural epithelium early in neural crest development produced an expansion of HNK1 immunoreactivity throughout the neural epithelium, although these cells did not undergo an epithelial/mesenchymal transformation. To test whether FoxD3 represses melanogenesis in early migrating neural crest cells, we knocked down expression in cultured neural crest with antisense oligonucleotides and in vivo by treatment with morpholino antisense oligonucleotides. Both experimental approaches resulted in an expansion of the melanoblast lineage, probably at the expense of neuronal and glial lineages. Conversely, persistent expression of FoxD3 in late-migrating neural crest cells using RCAS viruses resulted in the failure of melanoblasts to develop. We suggest that FoxD3 plays two important roles in neural crest development. First, it is involved in the segregation of the neural crest lineage from the neuroepithelium. Second, it represses melanogenesis, thereby allowing other neural crest derivatives to differentiate during the early stages of neural crest patterning.


1999 ◽  
Vol 65 (12) ◽  
pp. 5546-5553 ◽  
Author(s):  
Kazuhiro Iwashita ◽  
Tatsuya Nagahara ◽  
Hitoshi Kimura ◽  
Makoto Takano ◽  
Hitoshi Shimoi ◽  
...  

ABSTRACT We cloned the genomic DNA and cDNA of bglA, which encodes β-glucosidase in Aspergillus kawachii, based on a partial amino acid sequence of purified cell wall-bound β-glucosidase CB-1. The nucleotide sequence of the cloned bglA gene revealed a 2,933-bp open reading frame with six introns that encodes an 860-amino-acid protein. Based on the deduced amino acid sequence, we concluded that the bglA gene encodes cell wall-bound β-glucosidase CB-1. The amino acid sequence exhibited high levels of homology with the amino acid sequences of fungal β-glucosidases classified in subfamily B. We expressed the bglA cDNA inSaccharomyces cerevisiae and detected the recombinant β-glucosidase in the periplasm fraction of the recombinant yeast.A. kawachii can produce two extracellular β-glucosidases (EX-1 and EX-2) in addition to the cell wall-bound β-glucosidase.A. kawachii in which the bglA gene was disrupted produced none of the three β-glucosidases, as determined by enzyme assays and a Western blot analysis. Thus, we concluded that thebglA gene encodes both extracellular and cell wall-bound β-glucosidases in A. kawachii.


1999 ◽  
Vol 342 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Simon DOWLER ◽  
Richard A. CURRIE ◽  
C. Peter DOWNES ◽  
Dario R. ALESSI

We have identified a novel 280 amino acid protein which contains a putative myristoylation site at its N-terminus followed by an Src homology (SH2) domain and a pleckstrin homology (PH) domain at its C-terminus. It has been termed dual adaptor for phosphotyrosine and 3-phosphoinositides (DAPP1). DAPP1 is widely expressed and exhibits high-affinity interactions with PtdIns(3,4,5)P3 and PtdIns(3,4)P2, but not with other phospholipids tested. These observations predict that DAPP1 will interact with both tyrosine phosphorylated proteins and 3-phosphoinositides and may therefore play a role in regulating the location and/or activity of such proteins(s) in response to agonists that elevate PtdIns(3,4,5)P3 and PtdIns(3,4)P2.


2010 ◽  
Vol 142 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Jing Luo ◽  
Geng-Si Xi ◽  
Shu-Min Lü ◽  
Ke Li ◽  
Qing Li

AbstractThe semaphorin gene family plays important roles in axonal guidance in vertebrates and invertebrates. Semaphorin 2a, a member of the semaphorin family, belongs to class 2, which is found only in invertebrates. In our study, semaphorin 2a was cloned from the ant Polyrhachis vicina Roger. The full length of P. vicina semaphorin 2a (Pv-sema-2a) is 2763 base pairs (bp) and it contains a 5′-untranslated region (UTR) 92 bp long and a 3′-UTR 521 bp long. The open reading frame of Pv-sema-2a encodes a 716-amino-acid protein with a predicted molecular mass of 81.1 kilodaltons. Real-time quantitative reverse-transcription – polymerase chain reaction indicated that Pv-sema-2a mRNA is differentially expressed during P. vicina development, in the whole bodies as well as the heads of different castes. The high mRNA levels in embryos and pupae suggest that Pv-sema-2a plays an important role in ant development.


2003 ◽  
Vol 14 (1) ◽  
pp. 262-273 ◽  
Author(s):  
Masami Nagahama ◽  
Mie Suzuki ◽  
Yuko Hamada ◽  
Kiyotaka Hatsuzawa ◽  
Katsuko Tani ◽  
...  

VCP/p97 is involved in a variety of cellular processes, including membrane fusion and ubiquitin-dependent protein degradation. It has been suggested that adaptor proteins such as p47 and Ufd1p confer functional versatility to VCP/p97. To identify novel adaptors, we searched for proteins that interact specifically with VCP/p97 by using the yeast two-hybrid system, and discovered a novel VCP/p97-interacting protein named smallVCP/p97-interactingprotein (SVIP). Rat SVIP is a 76-amino acid protein that contains two putative coiled-coil regions, and potential myristoylation and palmitoylation sites at the N terminus. Binding experiments revealed that the N-terminal coiled-coil region of SVIP, and the N-terminal and subsequent ATP-binding regions (ND1 domain) of VCP/p97, interact with each other. SVIP and previously identified adaptors p47 and ufd1p interact with VCP/p97 in a mutually exclusive manner. Overexpression of full-length SVIP or a truncated mutant did not markedly affect the structure of the Golgi apparatus, but caused extensive cell vacuolation reminiscent of that seen upon the expression of VCP/p97 mutants or polyglutamine proteins in neuronal cells. The vacuoles seemed to be derived from endoplasmic reticulum membranes. These results together suggest that SVIP is a novelVCP/p97 adaptor whose function is related to the integrity of the endoplasmic reticulum.


2002 ◽  
Vol 46 (7) ◽  
pp. 2162-2168 ◽  
Author(s):  
Roberto Melano ◽  
Alejandro Petroni ◽  
Alicia Garutti ◽  
Héctor Alex Saka ◽  
Laura Mange ◽  
...  

ABSTRACT In a previous study, an analysis of 77 ampicillin-nonsusceptible (resistant plus intermediate categories) strains of Vibrio cholerae non-O1, non-O139, isolated from aquatic environment and diarrheal stool, showed that all of them produced a β-lactamase with a pI of 5.4. Hybridization or amplification by PCR with a probe for bla TEM or primers for bla CARB gene families was negative. In this work, an environmental ampicillin-resistant strain from this sample, ME11762, isolated from a waterway in the west region of Argentina, was studied. The nucleotide sequence of the structural gene of the β-lactamase was determined by bidirectional sequencing of a Sau3AI fragment belonging to this isolate. The gene encodes a new 288-amino-acid protein, designated CARB-7, that shares 88.5% homology with the CARB-6 enzyme; an overall 83.2% homology with PSE-4, PSE-1, CARB-3, and the Proteus mirabilis N29 enzymes; and 79% homology with CARB-4 enzyme. The gene for this β-lactamase could not be transferred to Escherichia coli by conjugation. The nucleotide sequence of the flanking regions of the bla CARB-7 gene showed the occurrence of three 123-bp V. cholerae repeated sequences, all of which were found outside the predicted open reading frame. The upstream fragment of the bla CARB-7 gene shared 93% identity with a locus situated inside V. cholerae's chromosome 2. These results strongly suggest the chromosomal location of the bla CARB-7 gene, making this the first communication of a β-lactamase gene located on the VCR island of the V. cholerae genome.


Holzforschung ◽  
2013 ◽  
Vol 67 (4) ◽  
pp. 463-471 ◽  
Author(s):  
Li-Ting Ma ◽  
Sheng-Yang Wang ◽  
Yen-Hsueh Tseng ◽  
Yi-Ru Lee ◽  
Fang-Hua Chu

Abstract The 2,3-oxidosqualene cyclases (OSCs) are a family of enzymes that have an important role in plant triterpene biosynthesis. In this study, an OSC gene designed EtLUS from Eleutherococcus trifoliatus has been cloned. EtLUS includes a 2292-bp open reading frame and encodes a 763-amino acid protein. EtLUS has an MLCYCR motif, which is conserved in lupeol synthases. Comparison of active-site residues and gene expression in yeast showed that EtLUS synthesizes lupeol. However, EtLUS has the highest sequence identity with β-amyrin synthases from Araliaceae rather than lupeol synthases, adding new perspective to the evolution of the OSCs of Araliaceae. Furthermore, EtLUS is upregulated in leaf tissues under methyl jasmonate treatment, which can be interpreted that lupeol and its derivatives play an ecological and physiological role in plant defense against pathogens and insect herbivores.


1993 ◽  
Vol 105 (3) ◽  
pp. 777-785 ◽  
Author(s):  
A.B. Vojtek ◽  
J.A. Cooper

CAP, an adenylyl cyclase associated protein, is present in Saccharomyces cerevisiae and Schizosaccharomyces pombe. In both organisms, CAP is bifunctional: the N-terminal domain binds to adenylyl cyclase, thereby enabling adenylyl cyclase to respond appropriately to upstream regulatory signals, such as RAS in S. cerevisiae; the C-terminal domain is required for cellular morphogenesis. Here, we describe the isolation of a cDNA encoding a CAP homolog from a higher eukaryote. The mouse CAP cDNA contains an open reading frame capable of encoding a 474 amino acid protein. The protein encoded by the mouse CAP cDNA shows extensive homology to the yeast CAP proteins, particularly in the central poly-proline rich region and in the C-terminal domain. By northern analysis, the CAP message appears to be ubiquitous, but not uniform. By indirect immunofluorescence, ectopically expressed mouse CAP protein is found in the cytoplasm of fibroblasts and, in migrating cells, at the leading edge. Expression of the mouse CAP cDNA in S. cerevisiae complements defects associated with loss of the yeast CAP carboxy-terminal domain. Hence, the function of the CAP carboxy-terminal domain has been conserved from yeast to mouse.


2008 ◽  
Vol 57 (1-6) ◽  
pp. 152-157 ◽  
Author(s):  
X. Ji ◽  
Y. Gai ◽  
J. Ma ◽  
C. Zheng ◽  
Z. Mu

Abstract A full-length cDNA encoding sedoheptulose-1,7-bisphosphatase (SBPase; EC 3.1.3.37) was cloned from mulberry (Morus alba var. multicaulis) by rapid amplification of cDNA ends (RACE). The cDNA consisted of 1,527 nucleotides with an open reading frame (ORF) of 1,179 nucleotides encoding a 393 amino acid protein of approximately 42.6 kDa. Sequence comparison analysis showed that mulberry SBPase (MSBPase) had high homology to other plant counterparts. Phylogenetic and molecular evolutionary analysis revealed that MSBPase fell into plant SBPase group. Moreover, SBPase and fructose-1,6-bisphosphatase (FBPase; EC 3.1.3.11) shared 28-32% identical residues, suggesting that the two enzymes originated from the same evolution branch. Molecular modeling indicated that each subunit of MSBPase was composed of α-helices and β-sheets joined by turns and loops, and folded into a structure of hexahedron shape which was very similar to FBPase.


1992 ◽  
Vol 119 (4) ◽  
pp. 737-747 ◽  
Author(s):  
I D Russell ◽  
D Tollervey

The four nucleolar proteins NOP1, SSB1, GAR1, and NSR1 of Saccharomyces cerevisiae share a repetitive domain composed of repeat units rich in glycine and arginine (GAR domain). We have cloned and sequenced a fifth member of this family, NOP3, and shown it to be essential for cell viability. The NOP3 open reading frame encodes a 415 amino acid protein with a predicted molecular mass of 45 kD, containing a GAR domain and an RNA recognition motif. NOP3-specific antibodies recognize a 60-kD protein by SDS-PAGE and decorate the nucleolus and the surrounding nucleoplasm. A conditional lethal mutation, GAL::nop3, was constructed; growth of the mutant strain in glucose medium represses NOP3 expression. In cells depleted of NOP3, production of cytoplasmic ribosomes is impaired. Northern analysis and pulse-chase labeling indicate that pre-rRNA processing is inhibited at the late steps, in which 27SB pre-rRNA is cleaved to 25S rRNA and 20S pre-rRNA to 18S rRNA.


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