Abstract
β-barrel outer membrane proteins (BOMPs) are essential components of outer membranes of Gram-negative bacteria and endosymbiotic organelles, usually involved in the transport of proteins and substrates across the membrane. Based on the analysis of our in silico BOMP predictor data for the Entamoeba histolytica genome, we detected a new transmembrane β-barrel domain-containing protein, EHI_192610. Sequence analysis revealed that this protein is unique to Entamoeba species, and it exclusively clusters with a homolog, EHI_099780, which is similarly lineage specific. Both proteins possess an N-terminal signal peptide sequence as well as multiple repeats that contain dyad hydrophobic periodicities. Data from immunofluorescence assay of trophozoites expressing the respective candidates showed the absence of colocalization with mitosomal marker, and interestingly demonstrated partial colocalization with endoplasmic reticulum (ER) proteins instead. Integration to organellar membrane was supported by carbonate fractionation assay and immunoelectron microscopy. CD analysis of reconstituted proteoliposomes containing EHI_192610 showed a spectrum demonstrating a predominant β-sheet structure, suggesting that this protein is β-strand rich. Furthermore, the presence of repeat regions with predicted transmembrane β-strand pairs in both EHI_192610 and EHI_099780, is consistent with the hypothesis that BOMPs originated from the amplification of ββ-hairpin modules, suggesting that the two Entamoeba-specific proteins are novel β-barrels, intriguingly localized partially to the ER membrane.
| Original language | English |
|---|---|
| Pages (from-to) | 3416-3432 |
| Number of pages | 17 |
| Journal | FEBS Journal |
| Volume | 286 |
| Issue number | 17 |
| DOIs | |
| Publication status | Published - 2019 Sep 1 |
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All Science Journal Classification (ASJC) codes
- Biochemistry
- Molecular Biology
- Cell Biology
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Novel lineage-specific transmembrane β-barrel proteins in the endoplasmic reticulum of Entamoeba histolytica. / Santos, Herbert J.; Imai, Kenichiro; Makiuchi, Takashi; Tomii, Kentaro; Paul, Brice Horton Ii; Nozawa, Akira; Okada, Kenta; Tozawa, Yuzuru; Nozaki, Tomoyoshi.
In: FEBS Journal, Vol. 286, No. 17, 01.09.2019, p. 3416-3432.Research output: Contribution to journal › Article
TY - JOUR
T1 - Novel lineage-specific transmembrane β-barrel proteins in the endoplasmic reticulum of Entamoeba histolytica
AU - Santos, Herbert J.
AU - Imai, Kenichiro
AU - Makiuchi, Takashi
AU - Tomii, Kentaro
AU - Paul, Brice Horton Ii
AU - Nozawa, Akira
AU - Okada, Kenta
AU - Tozawa, Yuzuru
AU - Nozaki, Tomoyoshi
PY - 2019/9/1
Y1 - 2019/9/1
N2 - β-barrel outer membrane proteins (BOMPs) are essential components of outer membranes of Gram-negative bacteria and endosymbiotic organelles, usually involved in the transport of proteins and substrates across the membrane. Based on the analysis of our in silico BOMP predictor data for the Entamoeba histolytica genome, we detected a new transmembrane β-barrel domain-containing protein, EHI_192610. Sequence analysis revealed that this protein is unique to Entamoeba species, and it exclusively clusters with a homolog, EHI_099780, which is similarly lineage specific. Both proteins possess an N-terminal signal peptide sequence as well as multiple repeats that contain dyad hydrophobic periodicities. Data from immunofluorescence assay of trophozoites expressing the respective candidates showed the absence of colocalization with mitosomal marker, and interestingly demonstrated partial colocalization with endoplasmic reticulum (ER) proteins instead. Integration to organellar membrane was supported by carbonate fractionation assay and immunoelectron microscopy. CD analysis of reconstituted proteoliposomes containing EHI_192610 showed a spectrum demonstrating a predominant β-sheet structure, suggesting that this protein is β-strand rich. Furthermore, the presence of repeat regions with predicted transmembrane β-strand pairs in both EHI_192610 and EHI_099780, is consistent with the hypothesis that BOMPs originated from the amplification of ββ-hairpin modules, suggesting that the two Entamoeba-specific proteins are novel β-barrels, intriguingly localized partially to the ER membrane.
AB - β-barrel outer membrane proteins (BOMPs) are essential components of outer membranes of Gram-negative bacteria and endosymbiotic organelles, usually involved in the transport of proteins and substrates across the membrane. Based on the analysis of our in silico BOMP predictor data for the Entamoeba histolytica genome, we detected a new transmembrane β-barrel domain-containing protein, EHI_192610. Sequence analysis revealed that this protein is unique to Entamoeba species, and it exclusively clusters with a homolog, EHI_099780, which is similarly lineage specific. Both proteins possess an N-terminal signal peptide sequence as well as multiple repeats that contain dyad hydrophobic periodicities. Data from immunofluorescence assay of trophozoites expressing the respective candidates showed the absence of colocalization with mitosomal marker, and interestingly demonstrated partial colocalization with endoplasmic reticulum (ER) proteins instead. Integration to organellar membrane was supported by carbonate fractionation assay and immunoelectron microscopy. CD analysis of reconstituted proteoliposomes containing EHI_192610 showed a spectrum demonstrating a predominant β-sheet structure, suggesting that this protein is β-strand rich. Furthermore, the presence of repeat regions with predicted transmembrane β-strand pairs in both EHI_192610 and EHI_099780, is consistent with the hypothesis that BOMPs originated from the amplification of ββ-hairpin modules, suggesting that the two Entamoeba-specific proteins are novel β-barrels, intriguingly localized partially to the ER membrane.
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U2 - 10.1111/febs.14870
DO - 10.1111/febs.14870
M3 - Article
C2 - 31045303
AN - SCOPUS:85066068349
VL - 286
SP - 3416
EP - 3432
JO - FEBS Journal
JF - FEBS Journal
SN - 1742-464X
IS - 17
ER -