scholarly journals Proteolytic processing of a coleopteran-specific δ-endotoxin produced by Bacillus thuringiensis var. tenebrionis

1989 ◽  
Vol 261 (1) ◽  
pp. 99-105 ◽  
Author(s):  
J Carroll ◽  
J Li ◽  
D J Ellar

Insecticidal protein delta-endotoxin crystals harvested from sporulated cultures of Bacillus thuringiensis var. tenebrionis contain a major polypeptide of 67 kDa and minor polypeptides of 73, 72, 55 and 46 kDa. During sporulation, only the 73 kDa polypeptide could be detected at stage I. The 67 kDa polypeptide was first detected at stage II and increased in concentration throughout the later stages of sporulation and after crystal release, with a concomitant decrease in the 73 kDa polypeptide. This change could be blocked by the addition of proteinase inhibitors. Trypsin or insect-gut-extract treatment of the delta-endotoxin crystals after solubilization resulted in a cleavage product of 55 kDa with asparagine-159 of the deduced amino acid sequence of the toxin [Höfte, Seurinck, van Houtven & Vaeck (1987) Nucleic Acids Res. 15, 71-83; Sekar, Thompson, Maroney, Bookland & Adang (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 7036-7040; McPherson, Perlak, Fuchs, Marrone, Lavrik & Fischhoff (1988) Biotechnology 6, 61-66] at the N-terminus. This polypeptide was found to be as toxic in vivo as native delta-endotoxin.

Gene ◽  
1987 ◽  
Vol 57 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Corinna Herrnstadt ◽  
Thomas E. Gilroy ◽  
Donna A. Sobieski ◽  
Brian D. Bennett ◽  
Frank H. Gaertner

1995 ◽  
Vol 69 (11) ◽  
pp. 7274-7277 ◽  
Author(s):  
J I Casal ◽  
J P Langeveld ◽  
E Cortés ◽  
W W Schaaper ◽  
E van Dijk ◽  
...  

1987 ◽  
Vol 7 (1) ◽  
pp. 294-304 ◽  
Author(s):  
D Pilgrim ◽  
E T Young

Alcohol dehydrogenase isoenzyme III (ADH III) in Saccharomyces cerevisiae, the product of the ADH3 gene, is located in the mitochondrial matrix. The ADH III protein was synthesized as a larger precursor in vitro when the gene was transcribed with the SP6 promoter and translated with a reticulocyte lysate. A precursor of the same size was detected when radioactively pulse-labeled proteins were immunoprecipitated with anti-ADH antibody. This precursor was rapidly processed to the mature form in vivo with a half-time of less than 3 min. The processing was blocked if the mitochondria were uncoupled with carbonyl cyanide m-chlorophenylhydrazone. Mutant enzymes in which only the amino-terminal 14 or 16 amino acids of the presequence were retained were correctly targeted and imported into the matrix. A mutant enzyme that was missing the amino-terminal 17 amino acids of the presequence produced an active enzyme, but the majority of the enzyme activity remained in the cytoplasmic compartment on cellular fractionation. Random amino acid changes were produced in the wild-type presequence by bisulfite mutagenesis of the ADH3 gene. The resulting ADH III protein was targeted to the mitochondria and imported into the matrix in all of the mutants tested, as judged by enzyme activity. Mutants containing amino acid changes in the carboxyl-proximal half of the ADH3 presequence were imported and processed to the mature form at a slower rate than the wild type, as judged by pulse-chase studies in vivo. The unprocessed precursor appeared to be unstable in vivo. It was concluded that only a small portion of the presequence contains the necessary information for correct targeting and import. Furthermore, the information for correct proteolytic processing of the presequence appears to be distinct from the targeting information and may involve secondary structure information in the presequence.


1993 ◽  
Vol 105 (4) ◽  
pp. 1137-1142 ◽  
Author(s):  
C.W. Morgans ◽  
R.R. Kopito

The 89 kDa NH2-terminal domain of erythrocyte ankyrin is composed almost entirely of 22 tandem repeats of a 33 amino acid sequence and constitutes the binding site for the cytoplasmic NH2-terminal domain of the erythrocyte anion exchanger, AE1. We have developed an assay to evaluate the in vivo interaction between a fragment of ankyrin corresponding to this domain (ANK90) and two non-erythroid anion exchangers, AE2 and AE3, that share considerable structural homology with AE1. Association was assessed by co-immunoprecipitation of ANK90-anion exchanger complexes from detergent extracts of cells cotransfected with plasmids encoding the ankyrin fragment and the anion exchanger or mutants thereof. ANK90 was co-immunoprecipitated with AE1 but not with an AE1 deletion mutant lacking the cytoplasmic NH2-terminal domain. Using this assay, we show that the brain anion exchanger AE3, but not the closely related homologue, AE2, is capable of binding to ankyrin.


1989 ◽  
Vol 9 (10) ◽  
pp. 4459-4466 ◽  
Author(s):  
K Kuroki ◽  
R Russnak ◽  
D Ganem

The preS1 surface glycoprotein of hepatitis B virus is targeted to the endoplasmic reticulum (ER) and is retained in this organelle when expressed in the absence of other viral gene products. The protein is also acylated at its N terminus with myristic acid. Sequences responsible for its ER retention have been identified through examination of mutants bearing lesions in the preS1 coding region. These studies reveal that such sequences map to the N terminus of the molecule, between residues 6 and 19. Molecules in which this region was present remained in the ER; those in which it had been deleted were secreted from the cell. Although all deletions which allowed efficient secretion also impaired acylation of the polypeptide, myristylation alone was not sufficient for ER retention: point mutations which eliminated myristylation did not lead to secretion. These data indicate that an essential element for ER retention resides in a 14-amino-acid sequence that is unrelated to previously described ER retention signals.


1994 ◽  
Vol 180 (1) ◽  
pp. 319-327 ◽  
Author(s):  
M C Pessolani ◽  
D R Smith ◽  
B Rivoire ◽  
J McCormick ◽  
S A Hefta ◽  
...  

The study of tissue-derived Mycobacterium leprae provides insights to the immunopathology of leprosy and helps identify broad molecular features necessary for mycobacterial parasitism. A major membrane protein (MMP-II) of in vivo-derived M. leprae previously recognized (Hunter, S.W., B. Rivoire, V. Mehra, B.R. Bloom, and P.J. Brennan. 1990. J. Biol. Chem. 265:14065) was purified from extracts of the organism and partial amino acid sequence obtained. This information allowed recognition, within one of the cosmids that encompass the entire M. leprae genome, of a complete gene, bfr, encoding a protein of subunit size 18.2 kD. The amino acid sequence deduced from the major membrane protein II (MMP-II) gene revealed considerable homology to several bacterioferritins. Analysis of the native protein demonstrated the iron content, absorption spectrum, and large native molecular mass (380 kD) of several known bacterioferritins. The ferroxidase-center residues typical of ferritins were conserved in the M. leprae product. Oligonucleotides derived from the amino acid sequence of M. leprae bacterioferritin enabled amplification of much of the MMP-II gene and the detection of homologous sequences in Mycobacterium paratuberculosis, Mycobacterium avium, Mycobacterium tuberculosis, Mycobacterium intracellulare, and Mycobacterium scrofulaceum. The role of this iron-rich protein in the virulence of M. leprae is discussed.


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