Molecular characterization of mitofilin (HMP), a mitochondria-associated protein with predicted coiled coil and intermembrane space targeting domains

1996 ◽  
Vol 109 (9) ◽  
pp. 2253-2264 ◽  
Author(s):  
P.R. Odgren ◽  
G. Toukatly ◽  
P.L. Bangs ◽  
R. Gilmore ◽  
E.G. Fey
Keyword(s):  
Polyclonal Antibodies ◽  
Limited Proteolysis ◽  
Coiled Coil ◽  
Cell Types ◽  
Cdna Clones ◽  
Intermembrane Space ◽  
Western Blots ◽  
Double Label ◽  
Helical Region

We have identified and characterized a human protein of the mitochondria which we call mitofilin. Using monoclonal and polyclonal antibodies, we have isolated cDNA clones and characterized mitofilin biochemically. It appears as a 90 and 91 kDa doublet in western blots and is translated from a single 2.7 kb mRNA. Antibodies raised against cellular and bacterially-expressed protein given identical cytoplasmic immunofluorescence and immunoblot results. Mitofilin co-localizes with mitochondria in immunofluorescence experiments and co-purifies with mitochondria. Double label studies show co-localization only with mitochondria and not with Golgi or endoplasmic reticulum. Co-localization with mitochondria is retained when actin or tubulin are de-polymerized, and mitofilin is expressed in all human cell types tested. The cDNA encodes a polypeptide with a central alpha-helical region with predicted coiled coil domains flanked by globular amino and carboxy termini. Unlike coiled coil motor proteins, mitofilin is resistant to detergent extraction. The presence of mitochondrial targeting and stop-transfer sequences, along with the accessibility of mitofilin to limited proteolysis suggests that it resides predominantly in the intermembrane space, consistent with immuno-electron micrographs which show mitofilin mainly at the mitochondrial periphery. The cDNA sequence of mitofilin is identical to that recently reported by Icho et al. (1994; Gene 144, 301–306) for a mRNA preferentially expressed in heart muscle (HMP), consistent with the high levels of mitochondria in cardiac myocytes.

Differences in the exposure of C- and N-terminal tubulin domains in cytoplasmic microtubules detected with domain-specific monoclonal antibodies

1989 ◽  
Vol 92 (3) ◽  
pp. 519-528 ◽  
Author(s):  
P. Draber ◽  
E. Draberova ◽  
I. Linhartova ◽  
V. Viklicky
Keyword(s):  
Monoclonal Antibodies ◽  
Polyclonal Antibodies ◽  
Limited Proteolysis ◽  
Antigenic Determinants ◽  
Alpha Tubulin ◽  
Domain Specific ◽  
Double Label ◽  
Cytoplasmic Microtubules ◽  
C And N ◽  
Terminal Domains

A panel of 11 monoclonal antibodies specific to alpha- or beta-tubulin subunits was used to study the location of tubulin molecules in cytoplasmic microtubules. Specificity of antibodies was confirmed by immunoblotting and immunofluorescence experiments on fixed cells. The limited proteolysis of tubulin with trypsin and chymotrypsin followed by immunoblotting demonstrated that the antibodies discriminated between structural domains of both subunits. Epitope mapping of isolated alpha-tubulin revealed that a set of antibodies against the N-terminal domain of the alpha-subunit (TU-01, TU-02, TU-03, TU-09, 6–11B-1) recognized at least four different antigenic determinants. Immunofluorescence staining of unfixed detergent-extracted cells showed that antibodies to determinants on C-terminal domains labelled microtubules, but these were not decorated with antibodies to N-terminal domains. The same results were obtained after microinjection of antibodies into living cells. The unchanged distribution of microtubules in injected cells was confirmed by double-label immunofluorescence with polyclonal antibodies. The data indicate that while parts of C-terminal domains of both subunits are exposed on the exterior of the microtubules, considerable regions of the N-terminal domains are either not exposed on the surface of cytoplasmic microtubules, or are masked by interacting proteins.

scholarly journals The Production and characterization of Polyclonal Antibodies Against Interferon Alpha in Mice

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Mehreen Fatima ◽  
Fatima Khalid ◽  
Azra Quraishi
Keyword(s):  
Immune Response ◽  
Autoimmune Diseases ◽  
Interferon Alpha ◽  
Polyclonal Antibodies ◽  
Mouse Serum ◽  
Interferon Production ◽  
Dot Blot ◽  
Western Blots ◽  
Response Activation

The polyclonal antibodies are used extensively for research purposes in many areas of biology, such as immunoprecipitation, histochemistry, enzyme linked immunosorbent assays (ELISA), diagnosis of disease and western blots. Typically, an animal’s immune system will generate a large group of antibodies that recognize several epitopes of a particular antigen. Interferon alpha plays an important role in immune response activation and therefore is of interest in studies related to autoimmune diseases. In this paper the production of antibodies against interferon was studied in order to quantify interferon production to analyze interferon levels in autoimmune disorders in the future. For the antibody production, one month old laboratory grade mice were injected with interferon alpha in combination with a Freund’s complete adjuvant for a course of five weeks after which the antibodies were obtained in mouse serum. Confirmation of the production of anti-interferon alpha antibodies was carried out by the Elisa, immune dot blot and western blot analysis. An interferon alpha of approximately 20.5-21.5 KDa was detected in immunedot blot test.  These antibodies may be produced in these mouse models commercially and could be used in future for treatment of autoimmune diseases by managing the interferon levels in the patients. Copyright(c) The Authors

Characterization of a Monoclonal Antibody, D73H, that Maps to a Highly Conserved Region on Fibrinogen Bβ Chain

2000 ◽  
Vol 84 (07) ◽  
pp. 43-48 ◽  
Author(s):  
B. J. Rybarczyk ◽  
M. Pereira ◽  
P. J. Simpson-Haidaris
Keyword(s):  
In Silico ◽  
Coiled Coil ◽  
In Silico Analysis ◽  
Antigenic Determinants ◽  
Human Fibrinogen ◽  
Western Blots ◽  
C Terminus ◽  
Probability Prediction ◽  
Silico Analysis

SummaryThe primary structure of fibrinogen is highly conserved across species, yet often times monoclonal antibodies produced against the fibrinogen of one species will not crossreact with the fibrinogen of another. Herein, we describe the production and characterization of murine MAb, D73H, raised against human fibrinogen. D73H crossreacts with a highly conserved epitope on the Bβ chain of fibrinogen from human, rat, bovine, guinea pig, and mouse. Western blotting revealed that D73H reacted with the Bβ chain of plasmin fragment D, localizing its epitope to Bβ134-461. A 7 kDa band was identified by D73H in Western blots of reduced fibrinogen CNBr-fragments. N-terminal sequencing mapped this fragment to Bβ243-253, further localizing the epitope to Bβ243-305. In silico analysis indicated that Bβ243-305 is predominantly hydrophilic, and surface probability prediction indicated three potential antigenic determinants corresponding to Bβ252-258, Bβ262-269, and Bβ279-286. Further in silico analysis of the crystal structure of fibrinogen fragment D-D indicated that Bβ262-269 (FGRKWDPY) is predominantly α-helical and located on the surface of the molecule adjacent to a bend imposed in the β chain at residue 260, which is near the junction between the rigid coiled-coil domain and the globular C-terminus. A synthetic peptide corresponding to Bβ261-272 competitively inhibited the binding of D73H to the Bβ chain of denatured intact fibrinogen and reduced and denatured Bβ chain in Western blots, experimentally proving the validity of these predictive algorithms. Together these data indicate that, although plasmin resistant, Bβ chain residues Bβ261-272 comprising the D73H epitope are highly conserved across species, surface exposed, and immunogenic.

scholarly journals Characterization of Palladin, a Novel Protein Localized to Stress Fibers and Cell Adhesions

2000 ◽  
Vol 150 (3) ◽  
pp. 643-656 ◽  
Author(s):  
Mana M. Parast ◽  
Carol A. Otey
Keyword(s):  
Cultured Cells ◽  
Focal Adhesions ◽  
Cell Types ◽  
Cell Junctions ◽  
Stress Fibers ◽  
Western Blots ◽  
Embryonic Tissues ◽  
Mouse Tissues ◽  
Antisense Constructs

Here, we describe the identification of a novel phosphoprotein named palladin, which colocalizes with α-actinin in the stress fibers, focal adhesions, cell–cell junctions, and embryonic Z-lines. Palladin is expressed as a 90–92-kD doublet in fibroblasts and coimmunoprecipitates in a complex with α-actinin in fibroblast lysates. A cDNA encoding palladin was isolated by screening a mouse embryo library with mAbs. Palladin has a proline-rich region in the NH2-terminal half of the molecule and three tandem Ig C2 domains in the COOH-terminal half. In Northern and Western blots of chick and mouse tissues, multiple isoforms of palladin were detected. Palladin expression is ubiquitous in embryonic tissues, and is downregulated in certain adult tissues in the mouse. To probe the function of palladin in cultured cells, the Rcho-1 trophoblast model was used. Palladin expression was observed to increase in Rcho-1 cells when they began to assemble stress fibers. Antisense constructs were used to attenuate expression of palladin in Rcho-1 cells and fibroblasts, and disruption of the cytoskeleton was observed in both cell types. At longer times after antisense treatment, fibroblasts became fully rounded. These results suggest that palladin is required for the normal organization of the actin cytoskeleton and focal adhesions.

scholarly journals Characterization of pinin, a novel protein associated with the desmosome-intermediate filament complex.

1996 ◽  
Vol 135 (4) ◽  
pp. 1027-1042 ◽  
Author(s):  
P Ouyang ◽  
S P Sugrue
Keyword(s):  
Intermediate Filament ◽  
Mdck Cells ◽  
Polyclonal Antibodies ◽  
Cdna Clones ◽  
Western Blots ◽  
Reading Frame ◽  
Rich Domain ◽  
293 Cells ◽  
Specific Variation ◽  
Conceptual Translation

We have identified a protein named pinin that is associated with the mature desmosomes of the epithelia (Ouyang, P., and S.P. Sugrue. 1992. J. Cell Biol. 118:1477-1488). We suggest that the function of pinin is to pin intermediate filaments to the desmosome. Therefore, pinin may play a significant role in reinforcing the intermediate filament-desmosome complex. cDNA clones coding for pinin were identified, using degenerative oligonucleotide probes that were based on the internal amino acid sequence of pinin for the screening of a cDNA library. Immunoblotting of expressed recombinant proteins with the monoclonal 08L antibody localized the 08L epitope to the carboxyl end of the protein. Polyclonal antibodies directed against fusion proteins immunoidentified the 140-kD protein in tissue extracts. Immunofluorescence analysis, using the antifusion protein antibody, demonstrated pinin at lateral epithelial boundaries, which is consistent with desmosomal localization. The conceptual translation product of the cDNA clones contained three unique domains: (a) a serine-rich domain; (b) a glutamine-proline, glutamine-leucine repeat domain; and (c) an acidic domain rich in glutamic acid. Although the 3' end of the open reading frame of the clone for pinin showed near identity to a partial cDNA isolated for a pig neutrophil phosphoprotein (Bellavite, P., F. Bazzoni, et al. 1990. Biochem. Biophys. Res. Commun. 170:915-922), the remaining sequence demonstrated little homology to known protein sequences. Northern blots of mRNA from chicken corneal epithelium, MDCK cells, and various human tissues indicated that pinin messages exhibit tissue-specific variation in size, ranging from 3.2 to 4.1 kb. Genomic Southern blots revealed the existence of one gene for pinin, suggesting alternative splicing of the mRNA. Expression of the full-length cDNA clones in human 293 cells and monkey COS-7 cells demonstrated that a 140-kD immunoreactive species on Western blots corresponded to pinin. Pinin cDNA transfected into the transformed 293 cells resulted in enhanced cell-cell adhesion. Immunofluorescence staining revealed that the expressed pinin protein was assembled to the lateral boundaries of the cells in contact, which is consistent with the staining pattern of pinin in epithelial cells.

scholarly journals Molecular Characterization of Annexin B2, B3 and B12 in Taenia multiceps

Genes ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 559 ◽  
Author(s):  
Cheng Guo ◽  
Yue Xie ◽  
Yuchen Liu ◽  
Ning Wang ◽  
Jiafei Zhan ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Polyclonal Antibodies ◽  
Parasite Development ◽  
Economic Losses ◽  
Mrna Levels ◽  
Western Blots ◽  
Taenia Multiceps ◽  
Homologous Genes ◽  
Coenurus Cerebralis

Coenurus cerebralis, the metacestode of Taenia multiceps, causes coenurosis, a disease severely affecting goat, sheep, cattle and yak farming and resulting in huge economic losses annually. Annexins bind calcium ions and play an important role in flatworm parasite development. To explore potential functions of annexins in T. multiceps, three homologous genes, namely, TmAnxB2, TmAnxB3 and TmAnxB12, were screened from the transcriptome dataset, amplified from C. cerebralis cDNA and subjected to bioinformatics analysis. Then, polyclonal antibodies recognizing the recombinant TmAnxB2 (rTmAnxB2) and rTmAnxB3 were prepared for localization of TmAnxB2 and TmAnxB3 in different tissues and developmental stages by immunofluorescence. The transcription of all three genes was also measured by relative fluorescent quantitative PCR. The sizes of rTmAnxB2, rTmAnxB3 and rTmAnxB12 were 58.00, 53.06 and 53.51 kDa, respectively, and rTmAnxB12 was unstable. Both rTmAnxB2 and rTmAnxB3 were recognized by goat-positive T. multiceps sera in Western blots. Immunofluorescence revealed that TmAnxB2 and TmAnxB3 were localized in the protoscolex and cyst wall and TmAnxB3 was also detected in adult cortex. TmAnxB2 and TmAnxB12 mRNA levels were determined to be highest in oncospheres and protoscolex, whereas transcription of TmAnxB3 was highest in scolex and immature segments. Taken together, these findings indicate that TmAnxB2 and TmAnxB12 may play critical roles in T. multiceps larvae, while TmAnxB3 may have important functions in adults. These results will lay the foundation for functional research of annexins in T. multiceps.

scholarly journals Molecular characterization of the 50-kD subunit of dynactin reveals function for the complex in chromosome alignment and spindle organization during mitosis.

1996 ◽  
Vol 132 (4) ◽  
pp. 617-633 ◽  
Author(s):  
C J Echeverri ◽  
B M Paschal ◽  
K T Vaughan ◽  
R B Vallee
Keyword(s):  
Coiled Coil ◽  
Cytoplasmic Dynein ◽  
Living Cells ◽  
Cdna Clones ◽  
Sedimentation Analysis ◽  
Spindle Poles ◽  
Chromosome Alignment ◽  
Dynactin Complex

Dynactin is a multi-subunit complex which has been implicated in cytoplasmic dynein function, though its mechanism of action is unknown. In this study, we have characterized the 50-kD subunit of dynactin, and analyzed the effects of its overexpression on mitosis in living cells. Rat and human cDNA clones revealed p50 to be novel and highly conserved, containing three predicted coiled-coil domains. Immunofluorescence staining of dynactin and cytoplasmic dynein components in cultured vertebrate cells showed that both complexes are recruited to kinetochores during prometaphase, and concentrate near spindle poles thereafter. Overexpression of p50 in COS-7 cells disrupted mitosis, causing cells to accumulate in a prometaphase-like state. Chromosomes were condensed but unaligned, and spindles, while still bipolar, were dramatically distorted. Sedimentation analysis revealed the dynactin complex to be dissociated in the transfected cultures. Furthermore, both dynactin and cytoplasmic dynein staining at prometaphase kinetochores was markedly diminished in cells expressing high levels of p50. These findings represent clear evidence for dynactin and cytoplasmic dynein codistribution within cells, and for the presence of dynactin at kinetochores. The data also provide direct in vivo evidence for a role for vertebrate dynactin in modulating cytoplasmic dynein binding to an organelle, and implicate both dynactin and dynein in chromosome alignment and spindle organization.

scholarly journals Purification and Characterization of Two Different α-l-Rhamnosidases, RhaA and RhaB, fromAspergillus aculeatus

2001 ◽  
Vol 67 (5) ◽  
pp. 2230-2234 ◽  
Author(s):  
Paloma Manzanares ◽  
Hetty C. van den Broeck ◽  
Leo H. de Graaff ◽  
Jaap Visser
Keyword(s):  
Amino Acid ◽  
Culture Filtrate ◽  
Polyclonal Antibodies ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Purification And Characterization ◽  
Aspergillus Aculeatus ◽  
Molecular Masses

ABSTRACT Two proteins exhibiting α-l-rhamnosidase activity, RhaA and RhaB, were identified upon fractionation and purification of a culture filtrate from Aspergillus aculeatus grown on hesperidin. Both proteins were shown to be N glycosylated and had molecular masses of 92 and 85 kDa, of which approximately 24 and 15%, respectively, were contributed by carbohydrate. RhaA and RhaB, optimally active at pH 4.5 to 5, showedK m and V maxvalues of 2.8 mM and 24 U/mg (RhaA) and 0.30 mM and 14 U/mg (RhaB) when tested forp-nitrophenyl-α-l-rhamnopyranoside. Both enzymes were able to hydrolyze α-1,2 and α-1,6 linkages to β-d-glucosides. Using polyclonal antibodies, the corresponding cDNA of both α-l-rhamnosidases,rhaA and rhaB, was cloned. On the basis of the amino acid sequences derived from the cDNA clones, both proteins are highly homologous (60% identity).

scholarly journals Pea2 protein of yeast is localized to sites of polarized growth and is required for efficient mating and bipolar budding.

1996 ◽  
Vol 135 (3) ◽  
pp. 725-739 ◽  
Author(s):  
N Valtz ◽  
I Herskowitz
Keyword(s):  
Coiled Coil ◽  
Cell Types ◽  
Cell Polarization ◽  
Polarized Growth ◽  
Coiled Coil Domain ◽  
Cell Biol ◽  
Two Phases ◽  
Diploid Cells ◽  
Novel Protein

Saccharomyces cerevisiae exhibits polarized growth during two phases of its life cycle, budding and mating. The site for polarization during vegetative growth is determined genetically: a and alpha haploid cells exhibit an axial budding pattern, and a/alpha diploid cells exhibit a bipolar pattern. During mating, each cell polarizes towards its partner to ensure efficient mating. SPA2 is required for the bipolar budding pattern (Snyder. M 1989. J. Cell Biol. 108:1419-1429; Zahner, J.A., H.A. Harkins, and J.R. Pringle. 1996. Mol. Cell. Biol. 16:1857-1870) and polarization during mating (Snyder, M., S. Gehrung, and B.D. Page. 1991. J. Cell Biol. 114: 515-532). We previously identified mutants defective in PEA2 and SPA2 which alter cell polarization in the presence of mating pheromone in a similar manner (Chenevert, J., N. Valtz, and I. Herskowitz. 1994. Genetics, 136:1287-1297). Here we report the further characterization of these mutants. We have found that PEA2 is also required for the bipolar budding pattern and that it encodes a novel protein with a predicted coiled-coil domain. Pea2p is expressed in all cell types and is localized to sites of polarized growth in budding and mating cells in a pattern similar to Spa2p, Pea2p and Spa2p exhibit interdependent localization: Spa2p is produced in pea2 mutants but fails to localize properly; Pea2p is not stably produced in spa2 mutants. These results suggest that Pea2p and Spa2p function together as a complex to generate the bipolar budding pattern and to guarantee proper polarization during mating.

Sign in / Sign up

Export Citation Format

Share Document