scholarly journals Specific substitutions at amino acid 256 of the sarcoplasmic/endoplasmic reticulum Ca2+transport ATPase mediate resistance to thapsigargin in thapsigargin-resistant hamster cells.

1998 ◽  
Vol 273 (21) ◽  
pp. 13366
Author(s):  
Myounghee Yu ◽  
Lilin Zhong ◽  
Arun K. Rishi ◽  
Mohammed Khadeer ◽  
Giuseppe Inesi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Transport Atpase

scholarly journals Specific Substitutions at Amino Acid 256 of the Sarcoplasmic/Endoplasmic Reticulum Ca2+Transport ATPase Mediate Resistance to Thapsigargin in Thapsigargin-resistant Hamster Cells

1998 ◽  
Vol 273 (6) ◽  
pp. 3542-3546 ◽  
Author(s):  
Myounghee Yu ◽  
Lilin Zhang ◽  
Arun K. Rishi ◽  
Mohammed Khadeer ◽  
Giuseppe Inesi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Transport Atpase

scholarly journals Reversal of the Ca2+ pump of blood platelets

1995 ◽  
Vol 306 (1) ◽  
pp. 35-38 ◽  
Author(s):  
J C Benech ◽  
H Wolosker ◽  
L de Meis
Keyword(s):  
Skeletal Muscle ◽  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Sarcoplasmic Reticulum ◽  
Blood Platelets ◽  
Specific Inhibitor ◽  
Amino Acid Sequences ◽  
Transport Systems ◽  
Muscle Enzyme ◽  
Transport Atpase

In this study, the endoplasmic Ca2+ transport ATPase of blood platelets was compared with the Ca2+ ATPase of sarcoplasmic reticulum skeletal muscle. Similar to the muscle enzyme, the Ca2+ ATPase from platelets was found to catalyse an ATP<-->P(i) exchange both in the presence and in the absence of a transmembrane Ca2+ gradient. When platelet vesicles are loaded with Ca2+ and diluted in medium containing ADP, P(i) and EGTA, the ATPase catalyses Ca2+ efflux coupled to synthesis of ATP. The stoichiometry between Ca2+ ion released and ATP synthesized by platelet Ca2+ ATPase is 1, while that of skeletal muscle is 2. Thapsigargin, a specific inhibitor of sarcoplasmic/endoplasmic reticulum Ca2+ ATPases, inhibited both the Ca(2+)-dependent ATPase activity and the reversal of the platelet Ca2+ pump. The possibility is discussed that the differences observed between the two transport systems is related to the distinct amino acid sequences of the enzymes.

Cloning and characterization of sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) from crayfish axial muscle. Sarco/Endoplasmic Reticulum Ca(2+)-ATPase

2000 ◽  
Vol 203 (22) ◽  
pp. 3411-3423 ◽  
Author(s):  
Z. Zhang ◽  
D. Chen ◽  
M.G. Wheatly
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Procambarus Clarkii ◽  
Muscle Growth ◽  
Abdominal Muscle ◽  
Northern Analysis ◽  
Specific Expression ◽  
Loop Region ◽  
Moulting Cycle

The discontinuous pattern of muscle growth during the moulting cycle of a freshwater crustacean (the crayfish Procambarus clarkii) was used as a model system to examine the regulation of the expression of Sarco/Endoplasmic Reticulum Ca(2+)-ATPase (SERCA). We describe the cloning, sequencing and characterization of a novel SERCA cDNA (3856 bp) obtained from crayfish axial abdominal muscle by reverse transcription/polymerase chain reaction (RT-PCR) followed by rapid amplification of cDNA ends (RACE). This complete sequence contains a 145 base pair (bp) noncoding region at the 5′ end, a 3006 bp open reading frame coding for 1002 amino acid residues with a molecular mass of 110 kDa and 705 bp of untranslated region at the 3′ end. This enzyme contains all the conserved domains found in ‘P’-type ATPases, and the hydropathy profile suggests a transmembrane organization typical of other SERCAs. It exhibits 80% amino acid identity with Drosophila melanogaster SERCA, 79% identity with Artemia franciscana SERCA, 72% identity with rabbit fast-twitch muscle neonatal isoform SERCA1b, 71% identity with slow-twitch muscle isoform SERCA2 and 67% identity with SERCA3. Sequence alignment revealed that regions anchoring the cytoplasmic domain in the membrane were highly conserved and that most differences were in the NH(2) terminus, the central loop region and the COOH terminus. Northern analysis of total RNA from crayfish tissues probed with the 460 bp fragment initially isolated showed four bands (7.6, 7.0, 5.8 and 4.5 kilobases) displaying tissue-specific expression. SERCA was most abundant in muscle (axial abdominal, cardiac and stomach), where it is involved in Ca(2+) resequestration during relaxation, and in eggs, where it may be implicated in early embryogenesis. The level of SERCA mRNA expression in axial abdominal muscle varied during the moulting cycle as determined by slot-blot analysis. SERCA expression was greatest during intermoult and decreased to approximately 50% of this level during pre- and postmoult. Patterns of gene expression for SERCA and other sarcomeric proteins during the crustacean moulting cycle may be regulated by ecdysteroids and/or mechanical stimulation.

Novel N-terminal amino acid sequence required for retention of a hepatitis B virus glycoprotein in the endoplasmic reticulum

1989 ◽  
Vol 9 (10) ◽  
pp. 4459-4466 ◽  
Author(s):  
K Kuroki ◽  
R Russnak ◽  
D Ganem
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Amino Acid Sequence ◽  
Essential Element ◽  
Viral Gene ◽  
Er Retention ◽  
B Virus ◽  
N Terminus

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.

scholarly journals Direct Binding of Cisplatin to p22phox, an Endoplasmic Reticulum (ER) Membrane Protein, Contributes to Cisplatin Resistance in Oral Squamous Cell Carcinoma (OSCC) Cells

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3815
Author(s):  
Chih-Chang Hung ◽  
Fu-An Li ◽  
Shih-Shin Liang ◽  
Ling-Feng Wang ◽  
I-Ling Lin ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Oral Squamous Cell Carcinoma ◽  
Membrane Protein ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Point Mutations ◽  
Prolonged Treatment ◽  
Er Membrane

Prolonged treatment with cisplatin (CDDP) frequently develops chemoresistance. We have previously shown that p22phox, an endoplasmic reticulum (ER) membrane protein, confers CDDP resistance by blocking CDDP nuclear entry in oral squamous cell carcinoma (OSCC) cells; however, the underlying mechanism remains unresolved. Using a fluorescent dye-labeled CDDP, here we show that CDDP can bind to p22phox in both cell-based and cell-free contexts. Subsequent detection of CDDP-peptide interaction by the Tris-Tricine-based electrophoresis revealed that GA-30, a synthetic peptide matching a region of the cytosolic domain of p22phox, could interact with CDDP. These results were further confirmed by liquid chromatography–mass spectrometry (LC–MS) analysis, from which MA-11, an 11-amino acid subdomain of the GA-30 domain, could largely account for the interaction. Amino acid substitutions at Cys50, Met65 and Met73, but not His72, significantly impaired the binding between CDDP and the GA-30 domain, thereby suggesting the potential CDDP-binding residues in p22phox protein. Consistently, the p22phox point mutations at Cys50, Met65 and Met73, but not His72, resensitized OSCC cells to CDDP-induced cytotoxicity and apoptosis. Finally, p22phox might have binding specificity for the platinum drugs, including CDDP, carboplatin and oxaliplatin. Together, we have not only identified p22phox as a novel CDDP-binding protein, but further highlighted the importance of such a drug-protein interaction in drug resistance.

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