Synthesis and Secretion of Plasminogen Activators and plasminogen Activator Inhibitor by Endothelial Cells
Cornelis Kluft in Tissue-Type Plasminogen Activator (t-PA): Physiological and Clinical Aspects, 1988
The rapid release of peptides from cells can occur by various mechanisms. First, the protein can be released from secretion granula, which are stored in the cell.123,124 Second, it may be released from a storage pool on the cell surface. It has been demonstrated that uPA is bound to the surface of monocytes/macrophages146 and endothelial cells.125 Both mechanisms require intra- or extracellular sorting mechanisms, usually realized by receptors or specific binding sites.124,126,150 The secretory proteins accumulate in/on nonstimulated secretory cells. The basis of the third mechanism is not a storage pool, but the continuous turnover of proteins. Several hormones, including prolactin and parathyroid hormone, are continuously synthesized and degraded within a quiescent endocrine cell. Upon stimulation, the cellular flux of secretory protein moves from the degradation site to the plasma membrane, resulting in a rapid release.127,128 The intracellular level of secretory proteins will then be low and will be nearly the same in quiescent and stimulated cells.
INTRODUCTION
David M. Gibson, Robert A. Harris in Metabolic Regulation in Mammals, 2001
(b) Another major parameter is the provision of substrates through membrane transport systems, e.g. the influx of glucose into the muscle cell by a specific transport protein (Chapter 6). Indeed membrane-bounded compartments of eukaryotic cells (ligure I.I) dramatically influence the pattern of metabolic flows by the separation of multienzyme systems: fatty acid oxidation and oxidative phosphorylation in mitochondria; fatty acid synthesis and glycolysis in the cytosol; secretory protein maturation in the golgi and endoplasmic reticulum; acidic proteolysis in Ivsosomcs; and the separation ol gene expression (transcription) in the nucleus from protein synthesis (transía tion) in the cytosol. Various controlling mechanisms regulate the traffic of metabolites and proteins passing from one compartment to another.
Intracellular Maturation of Acute Phase Proteins
Andrzej Mackiewicz, Irving Kushner, Heinz Baumann in Acute Phase Proteins, 2020
During the assembly of a secretory protein, the first 15 to 30 amino acid residues — the signal sequence — serve to direct the synthetic machinery to the endoplasmic reticulum (ER). Further elongation results in the progressive translocation of the polypeptide into the lumen of the ER and the removal of the signal sequence.3 The secretory proteins are then transported by vesicles to the Golgi complex (GC) via a tubulo-vesicular system, usually referred to as the intermediate compartment (Figure 1).4,5
Immunoinformatics driven construction of multi-epitope vaccine candidate against Ascaris lumbricoides using its entire immunogenic epitopes
Published in Expert Review of Vaccines, 2021
Rimanpreet Kaur, Naina Arora, Suraj Singh Rawat, Anand Kumar Keshri, Neha Singh, Sumit Kumar Show, Pramod Kumar, Amit Mishra, Amit Prasad
The membrane proteins and excretory/secretory proteins are the first parasitic antigens that interact with the host immune system and induce an immunological response (activation/suppression). The signal peptides present on the N-terminal of proteins determine their fate to mark as secretory protein or to be located on the cell membrane. The Signal P 5.0 server (http://www.cbs.dtu.dk/services/SignalP/index.php) was used for this purpose [19]. The signal peptide prediction alone does not define the exact location of the proteins, so other servers were also used to find the membrane proteins, Deeploc server (http://www.cbs.dtu.dk/services/DeepLoc-1.0/index.php) and WolfPsort (https://wolfpsort.hgc.jp/), it predicted the subcellular localizations of proteins in the cell and the common membrane proteins thus identified were used for further analysis [20,21].
Salamanders and caecilians, neglected from the chemical point of view
Published in Toxin Reviews, 2022
Isadora Alves de Vasconcelos, Jéssica Oliveira de Souza, Jessica Schneider de Castro, Carlos José Correia de Santana, Ana Carolina Martins Magalhães, Mariana de Souza Castro, Osmindo Rodrigues Pires Júnior
Comparing concentrations of skin glands from head and posterior regions of S. annulatus, it was observed that the head secretion has a transparent viscous nature and the posterior region secretion presents an opaquer fluid appearance (Jared et al.2018). The secretory protein content also differs, more abundant in the posterior region (11 mg/mL) than in the head (0.2 mg/mL). The electrophoretic and chromatographic profiles from both secretions also differ. It was suggested that, with the head shape S. annulatus, the mucous/lipid secretion serves as a lubricant and helps with locomotion, while the granular glands in posterior regions may provide a chemical defense.
R-spondin family biology and emerging linkages to cancer
Published in Annals of Medicine, 2023
Zhimin He, Jialin Zhang, Jianzhong Ma, Lei Zhao, Xiaodong Jin, Hongbin Li
The RSPO protein family consists of four members, RSPO1-4, with sequence similarity of 40 ∼ 60% and a common structure. Thus far, all reported RSPO proteins contain four major functional regions: two adjacent cysteine-rich furin-like domains (FU1-FU2), a TSP1 domain, and a BR domain with varying length at the C-terminus. As a typical secretory protein, the RSPO protein has a signal peptide with a length of 20 ∼ 25 amino acids at its N-terminus. After the signal peptide, there are two adjacent furin-like domains, which are rich in cysteine and are the most conserved regions in the RSPO protein structure (Figure 1).