scholarly journals Identification of a Regulated Alkaline Phosphatase, a Cell Surface-Associated Lipoprotein, in Mycobacterium smegmatis

2003 ◽  
Vol 185 (16) ◽  
pp. 4983-4991 ◽  
Author(s):  
Jordan Kriakov ◽  
Sun hee Lee ◽  
William R. Jacobs
Keyword(s):  
Alkaline Phosphatase ◽  
Cell Surface ◽  
Mycobacterium Smegmatis ◽  
Signal Sequence ◽  
Constitutive Expression ◽  
Phosphate Starvation ◽  
Alkaline Phosphatases ◽  
A Cell ◽  
Exported Protein ◽  
Transposon Insertions

ABSTRACT Although alkaline phosphatases are common in a wide variety of bacteria, there has been no prior evidence for alkaline phosphatases in Mycobacterium smegmatis. Here we report that transposon insertions in the pst operon, encoding homologues of an inorganic phosphate transporter, leads to constitutive expression of a protein with alkaline phosphatase activity. DNA sequence analysis revealed that M. smegmatis does indeed have a phoA gene that shows high homology to other phoA genes. The M. smegmatis phoA gene was shown to be induced by phosphate starvation and thus negatively regulated by the pst operon. Interestingly, the putative M. smegmatis PhoA has a hydrophobic N-terminal domain which resembles a lipoprotein signal sequence. The M. smegmatis PhoA was demonstrated to be an exported protein associated with the cell surface. Furthermore, immunoprecipitation of PhoA from [14C]acetate-labeled M. smegmatis cell lysates demonstrated that this phosphatase is a lipoprotein.

scholarly journals AG alpha 1 is the structural gene for the Saccharomyces cerevisiae alpha-agglutinin, a cell surface glycoprotein involved in cell-cell interactions during mating.

1989 ◽  
Vol 9 (8) ◽  
pp. 3155-3165 ◽  
Author(s):  
P N Lipke ◽  
D Wojciechowicz ◽  
J Kurjan
Keyword(s):  
Cell Surface ◽  
Fusion Protein ◽  
Structural Gene ◽  
Signal Sequence ◽  
Positive Control ◽  
Complementation Group ◽  
Surface Glycoprotein ◽  
Cell Surface Glycoprotein ◽  
Amino Terminal ◽  
A Cell

We have cloned the alpha-agglutinin structural gene, AG alpha 1, by the isolation of alpha-specific agglutination-defective mutants, followed by isolation of a complementing plasmid. Independently isolated alpha-specific agglutination-defective mutations were in a single complementation group, consistent with biochemical results indicating that the alpha-agglutinin is composed of a single polypeptide. Mapping results suggested that the complementation group identified by these mutants is allelic to the ag alpha 1 mutation identified previously. Expression of AG alpha 1 RNA was alpha specific and inducible by a-factor. Sequences similar to the consensus sequences for positive control by MAT alpha 1 and pheromone induction were found upstream of the AG alpha 1 initiation codon. The AG alpha 1 gene could encode a 650-amino-acid protein with a putative signal sequence, 12 possible N-glycosylation sites, and a high proportion of serine and threonine residues, all of which are features expected for the alpha-agglutinin sequence. Disruption of the AG alpha 1 gene resulted in failure to express alpha-agglutinin and loss of cellular agglutinability in alpha cells. An Escherichia coli fusion protein containing 229 amino acids of the AG alpha 1 sequence was recognized by an anti-alpha-agglutinin antibody. In addition, the ability of this antibody to inhibit agglutination was prevented by this fusion protein. These results indicate that AG alpha 1 encodes alpha-agglutinin. Features of the AG alpha 1 gene product suggest that the amino-terminal half of the protein contains the a-agglutinin binding domain and that the carboxy-terminal half contains a cell surface localization domain, possibly including a glycosyl phosphatidylinositol anchor.

Control and localization of the phosphatases in conidia of Neurospora crassa

1989 ◽  
Vol 35 (9) ◽  
pp. 830-835 ◽  
Author(s):  
E. Nahas
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Neurospora Crassa ◽  
Culture Medium ◽  
Alkaline Phosphatases ◽  
Cell Compartments ◽  
Surface Active Agents ◽  
Cell Enzyme ◽  
A Cell ◽  
Surface Active

Repressible acid, repressible alkaline, and constitutive alkaline phosphatases were studied with respect to their control and localization in conidia of Neurospora crassa. In contrast to constitutive alkaline phosphatase, the production and secretion of repressible phosphatases is regulated by phosphate level and pH of the culture medium. Phosphatase activity increased with conidial germination and was detectable partially in the growth medium after 5 h incubation. These enzymes were found to be located in different cell compartments. Part of the whole cell enzyme activity involved a soluble exoconidial fraction, and another part, a cell-bound enzyme that remained after successive washes. The cell-bound enzyme was sensitive to treatment with dilute acid and was thought to be located in the mural space. A third part of the enzyme activity was judged to be intracellular, as shown by treatments with surface-active agents and heat, which disrupted the conidia or destroyed the conidial permeability barriers. On the basis of these criteria, the constitutive alkaline phosphatase was considered to be more cryptic than the repressible phosphatases. The alkaline phosphatases were also active during heat treatment, suggesting they may be involved in the mechanism of secretion.Key words: Neurospora crassa, repressible acid phosphatase, repressible alkaline phosphatase, constitutive alkaline phosphatase, conidia.

scholarly journals SprB Is a Cell Surface Component of the Flavobacterium johnsoniae Gliding Motility Machinery

2008 ◽  
Vol 190 (8) ◽  
pp. 2851-2857 ◽  
Author(s):  
Shawn S. Nelson ◽  
Sreelekha Bollampalli ◽  
Mark J. McBride
Keyword(s):  
Cell Surface ◽  
Surface Protein ◽  
Gliding Motility ◽  
Wild Type ◽  
Polystyrene Microspheres ◽  
Flavobacterium Johnsoniae ◽  
A Cell ◽  
Transposon Insertions ◽  
Gliding Bacterium ◽  
Surface Adhesins

ABSTRACT Cells of the gliding bacterium Flavobacterium johnsoniae move rapidly over surfaces by an unknown mechanism. Transposon insertions in sprB resulted in cells that were defective in gliding. SprB is a highly repetitive 669-kDa cell surface protein, and antibodies against SprB inhibited the motility of wild-type cells. Polystyrene microspheres coated with antibodies against SprB attached to and were rapidly propelled along the cell surface, suggesting that SprB is one of the outermost components of the motility machinery. The movement of SprB along the cell surface supports a model of gliding motility in which motors anchored to the cell wall rapidly propel cell surface adhesins.

scholarly journals Characterization of Enterococcus faecalis Alkaline Phosphatase and Use in IdentifyingStreptococcus agalactiae Secreted Proteins

1999 ◽  
Vol 181 (18) ◽  
pp. 5790-5799 ◽  
Author(s):  
Martin H. Lee ◽  
Aphakorn Nittayajarn ◽  
R. Paul Ross ◽  
Cynthia B. Rothschild ◽  
Derek Parsonage ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Membrane Protein ◽  
Enterococcus Faecalis ◽  
Signal Sequence ◽  
Subcellular Location ◽  
Lactose Permease ◽  
Wild Type ◽  
Alkaline Phosphatases ◽  
Gram Positive ◽  
Gram Positive Bacteria

ABSTRACT We have identified and characterized an Enterococcus faecalis alkaline phosphatase (AP, encoded by phoZ). The predicted gene product shows homology with alkaline phosphatases from a variety of species; it has especially high similarity with two alkaline phosphatases from Bacillus subtilis. Expression ofphoZ in Escherichia coli, E. faecalis, Streptococcus agalactiae (group B streptococcus [GBS]), or Streptococcus pyogenes (group A streptococcus [GAS]) produces a blue-colony phenotype on plates containing a chromogenic substrate, 5-bromo-4-chloro-3-indolylphosphate (XP or BCIP). Two tests were made to determine if the activity of the enzyme is dependent upon the enzyme’s subcellular location. First, elimination of the signal sequence reduced AP activity to 3% of the wild-type activity (or less) in three species of gram-positive bacteria. Restoration of export, using the signal sequence from C5a peptidase, restored AP activity to at least 50% of that of the wild type. Second, we engineered two chimeric proteins in which AP was fused to either a periplasmic domain or a cytoplasmic domain of lactose permease (a membrane protein). In E. coli, the periplasmic fusion had 17-fold-higher AP activity than the cytoplasmic fusion. We concluded that AP activity is export dependent. The signal sequence deletion mutant, phoZΔss, was used to identify random genomic fragments from GBS that encode exported proteins or integral membrane proteins. Included in this set of fragments were genes that exhibited homology with the Rib protein (a cell wall protein from GBS) or with DppB (an integral membrane protein from GAS). AP acts as a reporter enzyme in GBS, GAS, and E. faecalis and is expected to be useful in a variety of gram-positive bacteria.

A cell-surface superoxide dismutase is a binding protein for peroxinectin, a cell-adhesive peroxidase in crayfish

1999 ◽  
Vol 112 (6) ◽  
pp. 917-925
Author(s):  
M.W. Johansson ◽  
T. Holmblad ◽  
P.O. Thornqvist ◽  
M. Cammarata ◽  
N. Parrinello ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Cell Surface ◽  
Signal Sequence ◽  
Binding Protein ◽  
Cell Surface Receptor ◽  
Cell Adhesive ◽  
Surface Receptor ◽  
A Cell ◽  
Polymerase Chain ◽  
Membrane Spanning

Peroxinectin, a cell-adhesive peroxidase (homologous to human myeloperoxidase), from the crayfish Pacifastacus leniusculus, was shown by immuno-fluorescence to bind to the surface of crayfish blood cells (haemocytes). In order to identify a cell surface receptor for peroxinectin, labelled peroxinectin was incubated with a blot of haemocyte membrane proteins. It was found to specifically bind two bands of 230 and 90 kDa; this binding was decreased in the presence of unlabelled peroxinectin. Purified 230/90 kDa complex also bound peroxinectin in the same assay. In addition, the 230 kDa band binds the crayfish beta-1,3-glucan-binding protein. The 230 kDa band could be reduced to 90 kDa, thus showing that the 230 kDa is a multimer of 90 kDa units. The peroxinectin-binding protein was cloned from a haemocyte cDNA library, using immuno-screening or polymerase chain reaction based on partial amino acid sequence of the purified protein. It has a signal sequence, a domain homologous to CuZn-containing superoxide dismutases, and a basic, proline-rich, C-terminal tail, but no membrane-spanning segment. In accordance, the 90 and 230 kDa bands had superoxide dismutase activity. Immuno-fluorescence of non-permeabilized haemocytes with affinity-purified antibodies confirmed that the crayfish CuZn-superoxide dismutase is localized at the cell surface; it could be released from the membrane with high salt. It was thus concluded that the peroxinectin-binding protein is an extracellular SOD (EC-SOD) and a peripheral membrane protein, presumably kept at the cell surface via ionic interaction with its C-terminal region. This interaction with a peroxidase seems to be a novel function for an SOD. The binding of the cell surface SOD to the cell-adhesive/opsonic peroxinectin may mediate, or regulate, cell adhesion and phagocytosis; it may also be important for efficient localized production of microbicidal substances.

AG alpha 1 is the structural gene for the Saccharomyces cerevisiae alpha-agglutinin, a cell surface glycoprotein involved in cell-cell interactions during mating

1989 ◽  
Vol 9 (8) ◽  
pp. 3155-3165
Author(s):  
P N Lipke ◽  
D Wojciechowicz ◽  
J Kurjan
Keyword(s):  
Cell Surface ◽  
Fusion Protein ◽  
Structural Gene ◽  
Signal Sequence ◽  
Positive Control ◽  
Complementation Group ◽  
Surface Glycoprotein ◽  
Cell Surface Glycoprotein ◽  
Amino Terminal ◽  
A Cell

We have cloned the alpha-agglutinin structural gene, AG alpha 1, by the isolation of alpha-specific agglutination-defective mutants, followed by isolation of a complementing plasmid. Independently isolated alpha-specific agglutination-defective mutations were in a single complementation group, consistent with biochemical results indicating that the alpha-agglutinin is composed of a single polypeptide. Mapping results suggested that the complementation group identified by these mutants is allelic to the ag alpha 1 mutation identified previously. Expression of AG alpha 1 RNA was alpha specific and inducible by a-factor. Sequences similar to the consensus sequences for positive control by MAT alpha 1 and pheromone induction were found upstream of the AG alpha 1 initiation codon. The AG alpha 1 gene could encode a 650-amino-acid protein with a putative signal sequence, 12 possible N-glycosylation sites, and a high proportion of serine and threonine residues, all of which are features expected for the alpha-agglutinin sequence. Disruption of the AG alpha 1 gene resulted in failure to express alpha-agglutinin and loss of cellular agglutinability in alpha cells. An Escherichia coli fusion protein containing 229 amino acids of the AG alpha 1 sequence was recognized by an anti-alpha-agglutinin antibody. In addition, the ability of this antibody to inhibit agglutination was prevented by this fusion protein. These results indicate that AG alpha 1 encodes alpha-agglutinin. Features of the AG alpha 1 gene product suggest that the amino-terminal half of the protein contains the a-agglutinin binding domain and that the carboxy-terminal half contains a cell surface localization domain, possibly including a glycosyl phosphatidylinositol anchor.

scholarly journals Removal of covalently bound inositol from Torpedo acetylcholinesterase and mammalian alkaline phosphatases by deamination with nitrous acid. Evidence for a common membrane-anchoring structure

1987 ◽  
Vol 241 (2) ◽  
pp. 615-619 ◽  
Author(s):  
M G Low ◽  
A H Futerman ◽  
K E Ackermann ◽  
W R Sherman ◽  
I Silman
Keyword(s):  
Alkaline Phosphatase ◽  
Cell Surface ◽  
Nitrous Acid ◽  
Free Amino ◽  
Sugar Residue ◽  
Amino Group ◽  
Glycosidic Linkage ◽  
Alkaline Phosphatases ◽  
Membrane Anchoring ◽  
Deamination Reaction

Our earlier evidence suggested that both acetylcholinesterase and alkaline phosphatase are anchored to the cell surface via covalently-attached phosphatidylinositol [Low, Futerman, Ferguson & Silman (1986) Trends Biochem. Sci. 11, 212-215]. We now present chemical data, based upon a nitrous acid deamination reaction, showing that in both proteins the phosphatidylinositol moiety is attached through a glycosidic linkage to a sugar residue bearing a free amino group.

Identification and characterization of an immunogenic 22 kDa exported protein of Mycobacterium avium subspecies paratuberculosis

2005 ◽  
Vol 54 (11) ◽  
pp. 1083-1092 ◽  
Author(s):  
Chris Dupont ◽  
Keith Thompson ◽  
Cord Heuer ◽  
Brigitte Gicquel ◽  
Alan Murray
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Smegmatis ◽  
Signal Sequence ◽  
Mycobacterium Avium Subspecies Paratuberculosis ◽  
Mycobacterial Species ◽  
Gene Encoding ◽  
Exported Protein ◽  
Culture Supernatants ◽  
Identification And Characterization

An exported 22 kDa putative lipoprotein was identified in an alkaline phosphatase gene fusion library of Mycobacterium avium subsp. paratuberculosis and expressed in Mycobacterium smegmatis. The full nucleic acid sequence of the gene encoding P22 was determined and the ORF was cloned into a mycobacterial expression vector, enabling full-length P22 to be produced as a C-terminal polyhistidine-tagged protein in M. smegmatis. N-terminal sequencing of the recombinant protein confirmed cleavage of a signal sequence. Native P22 was detected in culture supernatants and cell sonicates of M. avium subsp. paratuberculosis strain 316F using rabbit antibody raised to recombinant P22. Investigation of the presence of similar genes in other mycobacterial species revealed that the gene was present in Mycobacterium avium subsp. avium and similar genes existed in Mycobacterium intracellulare and Mycobacterium scrofulaceum. Database searches showed that P22 belonged to the LppX/LprAFG family of mycobacterial lipoproteins also found in Mycobacterium leprae and in members of the Mycobacterium tuberculosis complex. P22 shared less than 75 % identity to these proteins. Recombinant P22 was able to elicit interferon-gamma secretion in blood from eight of a group of nine sheep vaccinated with a live attenuated strain of M. avium subsp. paratuberculosis (strain 316F) compared to none from a group of five unvaccinated sheep. Antibody to P22 was detected by Western blot analysis in 10 out of 11 vaccinated sheep, in two out of two clinically affected cows and in 11 out of 13 subclinically infected cows.

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