scholarly journals Functional Characterization of a Nup159p-containing Nuclear Pore Subcomplex

1998 ◽  
Vol 9 (12) ◽  
pp. 3475-3492 ◽  
Author(s):  
Naı̈ma Belgareh ◽  
Christine Snay-Hodge ◽  
Fabien Pasteau ◽  
Suzanne Dagher ◽  
Charles N. Cole ◽  
...  
Keyword(s):  
Protein Import ◽  
Functional Characterization ◽  
Nuclear Pore ◽  
Terminal Domain ◽  
Carboxyl Terminal Domain ◽  
Cytoplasmic Face ◽  
Rna Export ◽  
Carboxyl Terminal

Nup159p/Rat7p is an essential FG repeat–containing nucleoporin localized at the cytoplasmic face of the nuclear pore complex (NPC) and involved in poly(A)+RNA export and NPC distribution. A detailed structural–functional analysis of this nucleoporin previously demonstrated that Nup159p is anchored within the NPC through its essential carboxyl-terminal domain. In this study, we demonstrate that Nup159p specifically interacts through this domain with both Nsp1p and Nup82p. Further analysis of the interactions within the Nup159p/Nsp1p/Nup82p subcomplex using the nup82Δ108mutant strain revealed that a deletion within the carboxyl-terminal domain of Nup82p prevents its interaction with Nsp1p but does not affect the interaction between Nup159p and Nsp1p. Moreover, immunofluorescence analysis demonstrated that Nup159p is delocalized from the NPC in nup82Δ108 cells grown at 37°C, a temperature at which the Nup82Δ108p mutant protein becomes degraded. This suggests that Nup82p may act as a docking site for a core complex composed of the repeat-containing nucleoporins Nup159p and Nsp1p. In vivo transport assays further revealed that nup82Δ108and nup159-1/rat7-1 mutant strains have little if any defect in nuclear protein import and protein export. Together our data suggest that the poly(A)+RNA export defect previously observed in nup82 mutant cells might be due to the loss from the NPCs of the repeat-containing nucleoporin Nup159p.

scholarly journals Characterization of the Carboxyl-terminal Domain of the Rat Glucose-dependent Insulinotropic Polypeptide (GIP) Receptor

1999 ◽  
Vol 274 (35) ◽  
pp. 24593-24601 ◽  
Author(s):  
Michael B. Wheeler ◽  
Richard W. Gelling ◽  
Simon A. Hinke ◽  
Ba Tu ◽  
Raymond A. Pederson ◽  
...  
Keyword(s):  
Terminal Domain ◽  
Carboxyl Terminal Domain ◽  
Carboxyl Terminal ◽  
Gip Receptor

Carboxyl-terminal domain characterization of polyene-specific P450 hydroxylase in Pseudonocardia autotrophica

2016 ◽  
Vol 43 (11) ◽  
pp. 1625-1630 ◽  
Author(s):  
Min-Kyung Kim ◽  
Hyung-Jin Won ◽  
Hye-Jin Kim ◽  
Si-Sun Choi ◽  
Heung-Shick Lee ◽  
...  
Keyword(s):  
Terminal Domain ◽  
Carboxyl Terminal Domain ◽  
Carboxyl Terminal

scholarly journals The rare sugar N-acetylated viosamine is a major component of Mimivirus fibers

2017 ◽  
Vol 292 (18) ◽  
pp. 7385-7394 ◽  
Author(s):  
Francesco Piacente ◽  
Cristina De Castro ◽  
Sandra Jeudy ◽  
Matteo Gaglianone ◽  
Maria Elena Laugieri ◽  
...  
Keyword(s):  
Structural Model ◽  
Functional Characterization ◽  
Virus Genome ◽  
Amino Group ◽  
Rare Sugar ◽  
Functional Annotations ◽  
Terminal Domain ◽  
Icosahedral Capsid

The giant virus Mimivirus encodes an autonomous glycosylation system that is thought to be responsible for the formation of complex and unusual glycans composing the fibers surrounding its icosahedral capsid, including the dideoxyhexose viosamine. Previous studies have identified a gene cluster in the virus genome, encoding enzymes involved in nucleotide-sugar production and glycan formation, but the functional characterization of these enzymes and the full identification of the glycans found in viral fibers remain incomplete. Because viosamine is typically found in acylated forms, we suspected that one of the genes might encode an acyltransferase, providing directions to our functional annotations. Bioinformatic analyses indicated that the L142 protein contains an N-terminal acyltransferase domain and a predicted C-terminal glycosyltransferase. Sequence analysis of the structural model of the L142 N-terminal domain indicated significant homology with some characterized sugar acetyltransferases that modify the C-4 amino group in the bacillosamine or perosamine biosynthetic pathways. Using mass spectrometry and NMR analyses, we confirmed that the L142 N-terminal domain is a sugar acetyltransferase, catalyzing the transfer of an acetyl moiety from acetyl-CoA to the C-4 amino group of UDP-d-viosamine. The presence of acetylated viosamine in vivo has also been confirmed on the glycosylated viral fibers, using GC-MS and NMR. This study represents the first report of a virally encoded sugar acetyltransferase.

scholarly journals Identification of a cyclase-associated protein (CAP) homologue in Dictyostelium discoideum and characterization of its interaction with actin.

1996 ◽  
Vol 7 (2) ◽  
pp. 261-272 ◽  
Author(s):  
U Gottwald ◽  
R Brokamp ◽  
I Karakesisoglou ◽  
M Schleicher ◽  
A A Noegel
Keyword(s):  
Plasma Membrane ◽  
Adenylyl Cyclase ◽  
Dictyostelium Discoideum ◽  
Direct Interaction ◽  
Actin Binding ◽  
Amino Terminal ◽  
Terminal Domain ◽  
Carboxyl Terminal Domain ◽  
Carboxyl Terminal

In search for novel actin binding proteins in Dictyostelium discoideum we have isolated a cDNA clone coding for a protein of approximately 50 kDa that is highly homologous to the class of adenylyl cyclase-associated proteins (CAP). In Saccharomyces cerevisiae the amino-terminal part of CAP is involved in the regulation of the adenylyl cyclase whereas the loss of the carboxyl-terminal domain results in morphological and nutritional defects. To study the interaction of Dictyostelium CAP with actin, the complete protein and its amino-terminal and carboxyl-terminal domains were expressed in Escherichia coli and used in actin binding assays. CAP sequestered actin in a Ca2+ independent way. This activity was localized to the carboxyl-terminal domain. CAP and its carboxyl-terminal domain led to a fluorescence enhancement of pyrene-labeled G-actin up to 50% indicating a direct interaction, whereas the amino-terminal domain did not enhance. In polymerization as well as in viscometric assays the ability of the carboxyl-terminal domain to sequester actin and to prevent F-actin formation was approximately two times higher than that of intact CAP. The sequestering activity of full length CAP could be inhibited by phosphatidylinositol 4,5-bisphosphate (PIP2), whereas the activity of the carboxyl-terminal domain alone was not influenced, suggesting that the amino-terminal half of the protein is required for the PIP2 modulation of the CAP function. In profilin-minus cells the CAP concentration is increased by approximately 73%, indicating that CAP may compensate some profilin functions in vivo. In migrating D. discoideum cells CAP was enriched at anterior and posterior plasma membrane regions. Only a weak staining of the cytoplasm was observed. In chemotactically stimulated cells the protein was very prominent in leading fronts. The data suggest an involvement of D. discoideum CAP in microfilament reorganization near the plasma membrane in a PIP2-regulated manner.

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