scholarly journals Membrane-associated guanylate kinase scaffolds organize a horizontal cell synaptic complex restricted to invaginating contacts with photoreceptors

2016 ◽  
Vol 525 (4) ◽  
pp. 850-867 ◽  
Author(s):  
Alejandro Vila ◽  
Christopher M. Whitaker ◽  
John O'Brien
Keyword(s):  
Horizontal Cell ◽  
Guanylate Kinase ◽  
Synaptic Complex

Identification and localization of connexin26 within the photoreceptor-horizontal cell synaptic complex

2001 ◽  
Vol 18 (2) ◽  
pp. 169-178 ◽  
Author(s):  
ULRIKE JANSSEN-BIENHOLD ◽  
KONRAD SCHULTZ ◽  
ALEXANDRA GELLHAUS ◽  
PETER SCHMIDT ◽  
JOSEF AMMERM??LLER ◽  
...  
Keyword(s):  
Horizontal Cell ◽  
Synaptic Complex

scholarly journals Intracellular recordings from gecko photoreceptors during light and dark adaptation.

1975 ◽  
Vol 66 (5) ◽  
pp. 617-648 ◽  
Author(s):  
J Kleinschmidt ◽  
J E Dowling
Keyword(s):  
Membrane Potential ◽  
Dark Adaptation ◽  
Horizontal Cell ◽  
Intracellular Recordings ◽  
Receptor Sensitivity ◽  
Intensity Curve ◽  
Voltage Range ◽  
Voltage Change ◽  
Sensitivity Change ◽  
Compression Treatment

Intracellular recordings were obtained from rods in the Gekko gekko retina and the adaptation characteristics of their responses studied during light and dark adaptation. Steady background illumination induced graded and sustained hyperpolarizing potentials and compressed the incremental voltage range of the receptor. Steady backgrounds also shifted the receptor's voltage-intensity curve along the intensity axis, and bright backgrounds lowered the saturation potential of the receptor. Increment thresholds of single receptors followed Weber's law over a range of about 3.5 log units and then saturated. Most of the receptor sensitivity change in light derived from the shift of the voltage-intensity curve, only little from the voltage compression. Treatment of the eyecup with sodium aspartate at concentrations sufficient to eliminate the beta-wave of the electroretinogram (ERG) abolished initial transients in the receptor response, possibly indicating the removal of horizontal cell feedback. Aspartate treatment, however, did not significantly alter the adaptation characteristics of receptor responses, indicating that they derive from processes intrinsic to the receptors. Dark adaptation after a strongly adapting stimulus was similarly associated with temporary elevation of membrane potential, initial lowering of the saturation potential, and shift of the voltage-intensity curve. Under all conditions of adaptation studied, small amplitude responses were linear with light intensity. Further, there was no unique relation between sensitivity and membrane potential suggesting that receptor sensitivity is controlled at least in part by a step of visual transduction preceding the generation of membrane voltage change.

Reorganization of horizontal cell processes in the developing FVB/N mouse retina

2001 ◽  
Vol 306 (2) ◽  
pp. 341-346 ◽  
Author(s):  
Sung-Jin Park ◽  
In-Beom Kim ◽  
Kyu-Ryong Choi ◽  
Jung-Il Moon ◽  
Su-Ja Oh ◽  
...  
Keyword(s):  
Horizontal Cell ◽  
Mouse Retina ◽  
Cell Processes

scholarly journals Site-Directed Mutagenesis Studies of Tn5 Transposase Residues Involved in Synaptic Complex Formation

2007 ◽  
Vol 189 (20) ◽  
pp. 7436-7441 ◽  
Author(s):  
Soheila Vaezeslami ◽  
Rachel Sterling ◽  
William S. Reznikoff
Keyword(s):  
Complex Formation ◽  
Catalytic Reactions ◽  
Site Directed Mutagenesis ◽  
Dna Interactions ◽  
Synaptic Complex ◽  
Biochemical Assays ◽  
Protein Dna Interactions ◽  
End Sequences ◽  
Tn5 Transposase ◽  
Cocrystal Structure

ABSTRACT Transposition (the movement of discrete segments of DNA, resulting in rearrangement of genomic DNA) initiates when transposase forms a dimeric DNA-protein synaptic complex with transposon DNA end sequences. The synaptic complex is a prerequisite for catalytic reactions that occur during the transposition process. The transposase-DNA interactions involved in the synaptic complex have been of great interest. Here we undertook a study to verify the protein-DNA interactions that lead to synapsis in the Tn5 system. Specifically, we studied (i) Arg342, Glu344, and Asn348 and (ii) Ser438, Lys439, and Ser445, which, based on the previously published cocrystal structure of Tn5 transposase bound to a precleaved transposon end sequence, make cis and trans contacts with transposon end sequence DNA, respectively. By using genetic and biochemical assays, we showed that in all cases except one, each of these residues plays an important role in synaptic complex formation, as predicted by the cocrystal structure.

scholarly journals Real-time analysis of RAG complex activity in V(D)J recombination

2016 ◽  
Vol 113 (42) ◽  
pp. 11853-11858 ◽  
Author(s):  
Jennifer Zagelbaum ◽  
Noriko Shimazaki ◽  
Zitadel Anne Esguerra ◽  
Go Watanabe ◽  
Michael R. Lieber ◽  
...  
Keyword(s):  
Real Time ◽  
Single Molecule ◽  
Conformational Changes ◽  
Signal Sequence ◽  
High Mobility ◽  
Time Analysis ◽  
Complex Activity ◽  
Synaptic Complex ◽  
Single Molecule Fret ◽  
Real Time Analysis

Single-molecule FRET (smFRET) and single-molecule colocalization (smCL) assays have allowed us to observe the recombination-activating gene (RAG) complex reaction mechanism in real time. Our smFRET data have revealed distinct bending modes at recombination signal sequence (RSS)-conserved regions before nicking and synapsis. We show that high mobility group box 1 (HMGB1) acts as a cofactor in stabilizing conformational changes at the 12RSS heptamer and increasing RAG1/2 binding affinity for 23RSS. Using smCL analysis, we have quantitatively measured RAG1/2 dwell time on 12RSS, 23RSS, and non-RSS DNA, confirming a strict RSS molecular specificity that was enhanced in the presence of a partner RSS in solution. Our studies also provide single-molecule determination of rate constants that were previously only possible by indirect methods, allowing us to conclude that RAG binding, bending, and synapsis precede catalysis. Our real-time analysis offers insight into the requirements for RSS–RSS pairing, architecture of the synaptic complex, and dynamics of the paired RSS substrates. We show that the synaptic complex is extremely stable and that heptamer regions of the 12RSS and 23RSS substrates in the synaptic complex are closely associated in a stable conformational state, whereas nonamer regions are perpendicular. Our data provide an enhanced and comprehensive mechanistic description of the structural dynamics and associated enzyme kinetics of variable, diversity, and joining [V(D)J] recombination.

Hepatocyte growth factor-regulated tyrosine kinase substrate (HGS) and guanylate kinase 1 (GUK1) are differentially expressed in GH-secreting adenomas

Pituitary ◽  
2006 ◽  
Vol 9 (2) ◽  
pp. 83-92 ◽  
Author(s):  
Anderson Alves da Rocha ◽  
Ricardo Rodrigues Giorgi ◽  
Sandra Valeria de Sa ◽  
Maria Lucia Correa-Giannella ◽  
Maria Angela Fortes ◽  
...  
Keyword(s):  
Growth Factor ◽  
Hepatocyte Growth Factor ◽  
Tyrosine Kinase ◽  
Differentially Expressed ◽  
Guanylate Kinase ◽  
Kinase Substrate ◽  
Hepatocyte Growth ◽  
Tyrosine Kinase Substrate
Sign in / Sign up

Export Citation Format

Share Document