The HydS C-terminal domain of the Thiocapsa bogorovii HydSL hydrogenase is involved in membrane anchoring and electron transfer

2021 ◽  
pp. 148492
Author(s):  
Makhmadyusuf K. Khasimov ◽  
Ekaterina P. Petushkova ◽  
Anna N. Khusnutdinova ◽  
Nikolay A. Zorin ◽  
Khorcheska A. Batyrova ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Terminal Domain ◽  
Membrane Anchoring

scholarly journals Membrane anchoring of the autoantigen GAD65 to microvesicles in pancreatic beta-cells by palmitoylation in the NH2-terminal domain.

1992 ◽  
Vol 118 (2) ◽  
pp. 309-320 ◽  
Author(s):  
S Christgau ◽  
H J Aanstoot ◽  
H Schierbeck ◽  
K Begley ◽  
S Tullin ◽  
...  
Keyword(s):  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Immunogold Electron Microscopy ◽  
Acid Decarboxylase ◽  
Gamma Aminobutyric Acid ◽  
Beta Cell Destruction ◽  
Terminal Domain ◽  
Membrane Anchoring ◽  
Major Target ◽  
Hydrophilic Molecule

Pancreatic beta-cells and gamma-aminobutyric acid (GABA)-secreting neurons both express the enzyme glutamic acid decarboxylase (GAD) which is a major target of autoantibodies associated with beta-cell destruction and impairment of GABA-ergic neurotransmitter pathways. The predominant form of GAD in pancreatic beta-cells, GAD65, is synthesized as a soluble hydrophilic molecule, which is modified to become firmly membrane anchored. Here we show by immunogold electron microscopy that GAD65 is localized to the membrane of small vesicles which are identical in size to small synaptic-like microvesicles in pancreatic beta-cells. The NH2-terminal domain of GAD65 is the site of a two-step modification, the last of which results in a firm membrane anchoring that involves posttranslational hydroxylamine sensitive palmitoylation. GAD65 can be released from the membrane by an apparent enzyme activity in islets, suggesting that the membrane anchoring step is reversible and potentially regulated. The hydrophobic modifications and consequent membrane anchoring of GAD65 to microvesicles that store its product GABA may be of functional importance and, moreover, significant for its selective role as an autoantigen.

scholarly journals The Cytoplasmic C-Terminal Domain of the Escherichia coli KdpD Protein Functions as a K+ Sensor

2006 ◽  
Vol 188 (5) ◽  
pp. 1950-1958 ◽  
Author(s):  
Marina C. Rothenbücher ◽  
Sandra J. Facey ◽  
Dorothee Kiefer ◽  
Marina Kossmann ◽  
Andreas Kuhn
Keyword(s):  
Escherichia Coli ◽  
Deletion Strain ◽  
Upstream Region ◽  
Amino Acid Residues ◽  
Extracellular Medium ◽  
E Coli ◽  
Transmembrane Segments ◽  
Terminal Domain ◽  
Protein Functions ◽  
Membrane Anchoring

ABSTRACT The KdpD protein is a K+ sensor kinase located in the cytoplasmic membrane of Escherichia coli. It contains four transmembrane stretches and two short periplasmic loops of 4 and 10 amino acid residues, respectively. To determine which part of KdpD functions as a K+ sensor, genetic variants were constructed with truncations or altered arrangements of the transmembrane segments. All KdpD constructs were tested by complementation of an E. coli kdpD deletion strain for their ability to grow at a K+ concentration of 0.1 mM in the medium. A soluble protein composed of the C-terminal cytoplasmic domain was able to complement the kdpD deletion strain. In addition, analysis of the β-galactosidase activity of an E. coli strain which carries a transcriptional fusion of the upstream region of the kdpFABC operon and a promoterless lacZ gene revealed that this soluble KdpD mutant responds to changes in the K+ concentration in the extracellular medium. The results suggest that the sensing and response functions are both located in the C-terminal domain and might be modulated by the N-terminal domain as well as by membrane anchoring.

The N-terminal cysteine cluster is essential for membrane targeting of B/K protein

2001 ◽  
Vol 360 (2) ◽  
pp. 441-448 ◽  
Author(s):  
Mitsunori FUKUDA ◽  
Katsuhiko MIKOSHIBA
Keyword(s):  
Transmembrane Domain ◽  
Protein Motif ◽  
Binding Motifs ◽  
Trans Golgi Network ◽  
Terminal Domain ◽  
C Terminus ◽  
Type C ◽  
Golgi Network ◽  
Membrane Anchoring ◽  
Specific Ligand

B/K protein belongs to a family of C-terminal-type (C-type) tandem C2 proteins that contain two C2 Ca2+-binding motifs at the C-terminus. Although other C-type tandem C2 proteins have been found to have a unique N-terminal domain that is involved in membrane anchoring (e.g. synaptotagmin) or specific ligand binding (e.g. rabphilin-3A and Doc2), no research has been conducted on the function of the N-terminal domain of B/K protein. In this study we showed that despite lacking a transmembrane domain, both native and recombinant B/K proteins are tightly bound to the membrane fraction, which was completely resistant to 0.1M Na2CO3, pH11, or 1M NaCl treatment. Deletion and mutation analyses indicated that the cysteine cluster at the N-terminal domain (consisting of seven cysteine residues, Cys-19, Cys-23, Cys-26, Cys-27, Cys-30, Cys-35 and Cys-36) is essential for the membrane localization of B/K protein. When wild-type B/K was expressed in PC12 cells, B/K proteins were localized mainly in the perinuclear region (trans-Golgi network), whereas mutant B/K proteins carrying Cys-to-Ala substitutions were present in the cytosol. Based on our findings, we propose that the N-terminal domain of B/K protein contains a novel cysteine-based protein motif that may allow B/K protein to localize in the trans-Golgi network.

Three muscle isoforms of α-actinin form unipolar actin bundles

1995 ◽  
Vol 53 ◽  
pp. 706-707
Author(s):  
K. A. Taylor ◽  
D. W. Taylor
Keyword(s):  
Cell Membrane ◽  
Actin Filaments ◽  
Striated Muscle ◽  
Subcellular Location ◽  
Binding Activity ◽  
Actin Binding ◽  
Physiological Importance ◽  
Terminal Domain ◽  
Dense Bodies ◽  
Membrane Anchoring

α-Actinin is an F-actin binding protein that is ubiquitous in eucaryotic cells. It is the smallest member of the spectrin superfamily and consists of two, identical polypeptide chains of 95-103 kDa. α-Actinin is an elongated molecule of 34 nm length and consists of a string of peptide domains with different functions. The N-terminal domain of ˜255 residues has actin binding activity, the central core consists of four 122 residues triple-helical repeats and the C-terminal domain contains two E-F hand Ca2+ binding motifs.The physiological importance α-actinin lies in its subcellular location and its interactions with other proteins. The F-actin crosslinking activity of α-actinin is its best known function. In striated muscle aactinin is found in the Z-disk. In smooth muscle, α-actinin is found in both cytoplasmic dense bodies, which are analogs of the Z-disk, and adhesion plaques, which are cell membrane anchoring sites of actin filaments. In dense bodies and Z-disks, oppositely oriented, unipolar bundles of actin filaments overlap so it has been commonly assumed that α-actinin is functioning as a bipolar crosslinker but the unipolar orientation of actin filaments at the cell membrane implies a unipolar bundling activity.

scholarly journals Yeast Nup84-Nup133 complex structure details flexibility and reveals conservation of the membrane anchoring ALPS motif

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah A. Nordeen ◽  
Daniel L. Turman ◽  
Thomas U. Schwartz
Keyword(s):  
Complex Structure ◽  
Eukaryotic Cell ◽  
Nuclear Pore ◽  
Structural Description ◽  
Endomembrane System ◽  
Cellular Functions ◽  
Terminal Domain ◽  
Dimeric Unit ◽  
High Flexibility ◽  
Membrane Anchoring

AbstractThe hallmark of the eukaryotic cell is the complex endomembrane system that compartmentalizes cellular functions. Transport into and out of the nucleus occurs through the nuclear pore complex (NPC). The heptameric Nup84 or Y complex is an essential scaffolding component of the NPC. Here we report two nanobody-bound structures: the full-length Nup84-Nup133 C-terminal domain complex and the Nup133 N-terminal domain, both from S. cerevisiae. Together with previously published structures, this work enables the structural description of the entire 575 kDa Y complex from one species. The structure of Nup84-Nup133CTD details the high flexibility of this dimeric unit of the Y complex. Further, the Nup133NTD contains a structurally conserved amphipathic lipid packing sensor motif, confirmed by liposome interaction studies. The presented structures reveal important details about the function of the Y complex that affect our understanding of NPC structure and assembly.

scholarly journals Structure of the yeast Nup84-Nup133 complex details flexibility and reveals universal conservation of the membrane anchoring ALPS motif

2020 ◽  
Author(s):  
Sarah A. Nordeen ◽  
Daniel L. Turman ◽  
Thomas U. Schwartz
Keyword(s):  
Nuclear Pore Complex ◽  
Eukaryotic Cell ◽  
Nuclear Pore ◽  
Structural Description ◽  
Endomembrane System ◽  
Cellular Functions ◽  
Terminal Domain ◽  
Dimeric Unit ◽  
High Flexibility ◽  
Membrane Anchoring

AbstractThe hallmark of the eukaryotic cell is the complex endomembrane system that compartmentalizes cellular functions. Transport into and out of the nucleus, occurs through the Nuclear Pore Complex (NPC). The heptameric Nup84 or Y complex is an essential scaffolding component of the NPC. Here we report two nanobody-bound structures: the full-length Nup84-Nup133 C-terminal domain complex and the Nup133 N-terminal domain, both from S. cerevisiae. Together with previously published structures, this work enables the structural description of the entire 575 kDa Y complex, from one species. The structure of Nup84-Nup1 33CTD details the high flexibility of this dimeric unit of the Y complex. Further, the Nup133NTD contains a structurally conserved amphipathic lipid packing sensor (ALPS) motif, confirmed by liposome interaction studies. The new structures reveal important details about the function of the Y complex that affect our understanding of NPC structure and assembly.

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