Peripheral membrane proteins of sarcoplasmic and endoplasmic reticulum. Comparison of carboxyl-terminal amino acid sequences

1989 ◽  
Vol 67 (10) ◽  
pp. 696-702 ◽  
Author(s):  
Larry Fliegel ◽  
Kimberly Burns ◽  
Ken Wlasichuk ◽  
Marek Michalak
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Sarcoplasmic Reticulum ◽  
Membrane Proteins ◽  
Binding Protein ◽  
Amino Acid Sequences ◽  
Endoplasmic Reticulum Membrane ◽  
Peripheral Membrane Proteins ◽  
Carboxyl Terminal ◽  
Retention Signal

Peripheral endoplasmic reticulum membrane proteins residing in the lumen of the endoplasmic reticulum occupy the same space as other secreted proteins. The presence of a four amino acid salvage or retention signal (KDEL-COOH = Lys-Asp-Glu-Leu-COOH) at the carboxyl-terminal end of peripheral membrane proteins has been shown to represent a signal or an essential part of a signal for their retention within the endoplasmic reticulum membrane. In heart and skeletal muscle, a number of sarcoplasmic reticulum proteins have recently been identified which are peripheral membrane proteins. The high-affinity calcium-binding protein (55 kilodaltons (kDa)) appears to conform to the above described mechanisms and contains the KDEL carboxyl-terminal tetrapeptide. Thyroid hormone binding protein is present in the sarcoplasmic reticulum, in addition to its endoplasmic reticulum location, and has a modified but related tetrapeptide sequence (RDEL = Arg-Asp-Glu-Leu), which also probably functions as the retention signal. Calsequestrin and a 53-kDa glycoprotein, two other peripheral membrane proteins residing in the lumen of the sarcoplasmic reticulum, do not contain the KDEL retention signal. The sarcoplasmic reticulum may have developed a unique retention mechanism(s) for these muscle-specific proteins.Key words: sarcoplasmic reticulum, endoplasmic reticulum, amino acid sequences, peripheral membrane proteins, KDEL retention sequence.

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.

scholarly journals Purification and characterization of a uterine retinol-binding protein in the bitch

1995 ◽  
Vol 311 (2) ◽  
pp. 407-415 ◽  
Author(s):  
W C Buhi ◽  
I M Alvarez ◽  
V M Shille ◽  
M J Thatcher ◽  
J P Harney ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dna Sequences ◽  
Binding Protein ◽  
Amino Acid Content ◽  
Amino Acid Sequences ◽  
Retinol Binding Protein ◽  
Total Amino Acid ◽  
Major Protein ◽  
Serum Retinol ◽  
Two Dimensional Gel Electrophoresis

A major canine endometrial secreted protein (cP6, 23,000-M(r)) was purified by ion-exchange and gel-filtration chromatography and characterized by two-dimensional gel electrophoresis. Anti-[human retinol-binding protein (hRBP)] serum identified cP6 on immunoblot analysis and immunoprecipitated cP6 from culture medium. This major protein was also shown to bind [3H]retinol. N-terminal and internal amino acid sequences were determined and compared with previously identified protein, RNA, or DNA sequences. N-terminal analysis revealed that cP6 had high identity and similarity to serum retinol-binding proteins (RBPs), while internal sequence analysis showed a strong similarity to rat androgen-dependent epididymal protein and beta-lactoglobulins. Amino acid analysis, however, showed significant differences between these proteins and cP6 in both total amino acid content and certain selected amino acids. Immunohistochemical analysis showed staining for RBP only in the uterine luminal epithelium. These studies suggest that bitch endometrium secretes a family of proteins (cP6), some of which bind [3H]retinol, are immunologically related to the RBP family, and have N-terminal and internal sequences with a high similarity to RBP, beta-lactoglobulins and other members of the lipocalin family. This family of proteins may be important in early development for supplying retinol or derivatives to the developing embryo.

A head-activator binding protein is present in hydra in a soluble and a membrane-anchored form

Development ◽  
1999 ◽  
Vol 126 (18) ◽  
pp. 4077-4086 ◽  
Author(s):  
W. Hampe ◽  
J. Urny ◽  
I. Franke ◽  
S.A. Hoffmeister-Ullerich ◽  
D. Herrmann ◽  
...  
Keyword(s):  
Stem Cells ◽  
Amino Acid ◽  
Transmembrane Domain ◽  
Binding Protein ◽  
Amino Acid Sequences ◽  
Secreted Protein ◽  
Specific Antibodies ◽  
Head Activator ◽  
Carboxy Terminal

The neuropeptide head activator plays an important role for proliferation and determination of stem cells in hydra. By affinity chromatography a 200 kDa head-activator binding protein, HAB, was isolated from the multiheaded mutant of Chlorohydra viridissima. Partial amino acid sequences were used to clone the HAB cDNA which coded for a receptor with a unique alignment of extracellular modules, a transmembrane domain, and a short carboxy-terminal cytoplasmic tail. A mammalian HAB homologue with identical alignment of these modules is expressed early in brain development. Specific antibodies revealed the presence of HAB in hydra as a transmembrane receptor, but also as secreted protein, both capable of binding head activator. Secretion of HAB during regeneration and expression in regions of high determination potential hint at a role for HAB in regulating the concentration and range of action of head activator.

scholarly journals Stability and flexibility of marginally hydrophobic–segment stalling at the endoplasmic reticulum translocon

2016 ◽  
Vol 27 (6) ◽  
pp. 930-940 ◽  
Author(s):  
Yuichiro Kida ◽  
Yudai Ishihara ◽  
Hidenobu Fujita ◽  
Yukiko Onishi ◽  
Masao Sakaguchi
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Lipid Phase ◽  
Endoplasmic Reticulum Membrane ◽  
Dependent Manner ◽  
Transmembrane Segment ◽  
Conducting Channel ◽  
Transmembrane Segments ◽  
Lipid Environment ◽  
Sec61 Channel

Many membrane proteins are integrated into the endoplasmic reticulum membrane through the protein-conducting channel, the translocon. Transmembrane segments with insufficient hydrophobicity for membrane integration are frequently found in multispanning membrane proteins, and such marginally hydrophobic (mH) segments should be accommodated, at least transiently, at the membrane. Here we investigated how mH-segments stall at the membrane and their stability. Our findings show that mH-segments can be retained at the membrane without moving into the lipid phase and that such segments flank Sec61α, the core channel of the translocon, in the translational intermediate state. The mH-segments are gradually transferred from the Sec61 channel to the lipid environment in a hydrophobicity-dependent manner, and this lateral movement may be affected by the ribosome. In addition, stalling mH-segments allow for insertion of the following transmembrane segment, forming an Ncytosol/Clumen orientation, suggesting that mH-segments can move laterally to accommodate the next transmembrane segment. These findings suggest that mH-segments may be accommodated at the ER membrane with lateral fluctuation between the Sec61 channel and the lipid phase.

Characteristics of Two Forms of α-Amylases and Structural Implication

1999 ◽  
Vol 65 (10) ◽  
pp. 4652-4658 ◽  
Author(s):  
Kohji Ohdan ◽  
Takashi Kuriki ◽  
Hiroki Kaneko ◽  
Jiro Shimada ◽  
Toshikazu Takada ◽  
...  
Keyword(s):  
Amino Acid ◽  
Three Dimensional ◽  
Amino Acid Sequences ◽  
Dimensional Structure ◽  
Amino Acid Residues ◽  
Amylase Gene ◽  
Raw Starch ◽  
Raw Starch Binding ◽  
Terminal Amino ◽  
Carboxyl Terminal

ABSTRACT Complete (Ba-L) and truncated (Ba-S) forms of α-amylases fromBacillus subtilis X-23 were purified, and the amino- and carboxyl-terminal amino acid sequences of Ba-L and Ba-S were determined. The amino acid sequence deduced from the nucleotide sequence of the α-amylase gene indicated that Ba-S was produced from Ba-L by truncation of the 186 amino acid residues at the carboxyl-terminal region. The results of genomic Southern analysis and Western analysis suggested that the two enzymes originated from the same α-amylase gene and that truncation of Ba-L to Ba-S occurred during the cultivation of B. subtilis X-23 cells. Although the primary structure of Ba-S was approximately 28% shorter than that of Ba-L, the two enzyme forms had the same enzymatic characteristics (molar catalytic activity, amylolytic pattern, transglycosylation ability, effect of pH on stability and activity, optimum temperature, and raw starch-binding ability), except that the thermal stability of Ba-S was higher than that of Ba-L. An analysis of the secondary structure as well as the predicted three-dimensional structure of Ba-S showed that Ba-S retained all of the necessary domains (domains A, B, and C) which were most likely to be required for functionality as α-amylase.

scholarly journals Different Responses of Cytoplasmic and Endoplasmic Reticulum Hsp90 Genes from Eogystia hippophaecola (Lepidoptera: Cossidae) to Cold Stress

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 1039
Author(s):  
Qianqian Wang ◽  
Jing Tao ◽  
Yurong Li ◽  
Yabei Xu ◽  
Xinhai Liu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Amino Acid ◽  
Low Temperature ◽  
Cold Stress ◽  
Cold Tolerance ◽  
Response Times ◽  
Expression Patterns ◽  
Amino Acid Sequences ◽  
Sea Buckthorn ◽  
Open Reading Frames

Eogystia hippophaecola Hua, Chou, Fang et Chen (Lepidoptera: Cossidae) is an important borer pest of the sea buckthorn forest (Hippophae rhamnoides L.) in China. Its larvae, which are highly cold tolerant, mainly overwinter in sea buckthorn roots. Heat shock proteins (Hsps) are important molecular chaperones that have been linked to cold tolerance in insects. In this study, we cloned the open reading frames (ORFs) of two Hsp90 genes from E. hippophaecola, EhHsp90-1 and EhHsp90-2, and analyzed their expression under cold stress by qRT-PCR. EhHsp90-1 and EhHsp90-2 are 2154 and 2346 bp in length, respectively, encoding 717 and 781 amino acids. The deduced amino acid sequences contain the conserved signature sequences of the Hsp90 family and the C-terminus characteristic sequence of cytoplasmic or endoplasmic reticulum Hsp90 protein. Phylogenetic analysis revealed the amino acid sequences of EhHsp90-1 and EhHsp90-2 were very similar to the corresponding proteins from Lepidoptera. Under various low-temperature treatments lasting 2 h, EhHsp90-1 and EhHsp90-2 exhibited similar expression patterns, increasing first and then decreasing. At −5 °C, EhHsp90-1 was significantly up-regulated after 12 h, whereas EhHsp90-2 was up-regulated after just 1 h and reached its highest level at 2 h; however, the overall degree of upregulation was greater for EhHsp90-1. Subsequently, the expression level of EhHsp90-2 fluctuated with time. Our results suggest that the two Hsp90s play important roles in E. hippophaecola larvae response to cold stress, but that their response times and the magnitudes of their responses to low-temperature stress differed significantly, providing a theoretical basis for further studying the molecular mechanism of cold tolerance in E. hippophaecola larvae.

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