Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Recoverin”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed2002

Ca2+-dependent control of rhodopsin phosphorylation: recoverin and rhodopsin kinase.

Over many years until the middle of the 1980s, the main problem in vision research had been the mechanism of transducing the visual signal from photobleached rhodopsin to the cationic channels in the plasma membrane of a photoreceptor to trigger the electrophysiological response of the cell. After cGMP was proven to be the secondary messenger, the main intriguing question has become the mechanisms of negative feedback in photoreceptors to modulate their response to varying conditions of illumination. Although the mechanisms of light-adaptation are not completely understood, it is obvious that Ca2+ plays a crucial role in these mechanisms and that the effects of Ca2+ can be mediated by several Ca2+-binding proteins. One of them is recoverin. The leading candidate for the role of an intracellular target for recoverin is believed to be rhodopsin kinase, a member of a family of G-protein-coupled receptor kinases. The present review considers recoverin, rhodopsin kinase and their interrelationships in the in vitro as well as in vivo contexts.

Amino Acid Motifs↗
PubMed1995

Evidence against involvement of recoverin in autosomal recessive retinitis pigmentosa in 42 Spanish families.

Autosomal recessive retinitis pigmentosa (ARRP) is a degenerative disease of photoreceptors in which defects in the genes encoding rhodopsin, the beta subunit of rod phosphodiesterase (PDEB) and, recently, in the gene for rod cGMP-gated channel, have been reported. However, detailed genetic involvement has not been ascertained in the great majority of cases. Recoverin, another member of the light transduction pathway, is a candidate gene for ARRP. We report the first analyses of the involvement of the recoverin gene (RCV1) in 42 Spanish ARRP families. Linkage and homozygosity studies with an intragenic polymorphism and the close markers D17S945 and D17S786 ruled out RCV1 as the cause of ARRP in 38 pedigrees. In the four remaining families, single strand conformation polymorphism analysis of the recoverin-coding region detected no mutations in the parents or in the affected members. These results strongly suggest that mutations in the RCV1 gene are not responsible for ARRP in these families.

Base Sequence↗
PubMed1992

Identification of recoverin-like immunoreactivity in mouse brain.

Mouse brain was found by immunoblot analysis to have a protein of Mr 23,000 (P23k) that was clearly different from recoverin and was labeled with an antiserum raised against the NH2-terminus of recoverin. P23k could not be detected by an antiserum raised against the COOH-terminus of recoverin. Blots with 45Ca demonstrated that P23k bound Ca2+ and had a Ca(2+)-dependent membrane-binding property. Immunohistochemical studies provided the specific distribution of P23k in cerebral cortex and cerebellum.

Amino Acid Sequence↗
PubMed1991

Phosphorylation of recoverin, the calcium-sensitive activator of photoreceptor guanylyl cyclase.

Recoverin, a new calcium binding protein from bovine rod photoreceptor cells, activates guanylyl cyclase below a free calcium concentration of 200 nM. We show here that recoverin is phosphorylated by an endogenous kinase and Mg-ATP at the same decreased calcium concentration. The calcium-dependent activation of guanylyl cyclase is enhanced in the presence of ATP. We suggest that phosphorylation of recoverin reinforces the stimulation of guanylyl cyclase at decreased calcium concentrations.

Adenosine Triphosphate↗
PubMed1993

Three-dimensional structure of recoverin, a calcium sensor in vision.

Recoverin, a recently discovered member of the EF hand superfamily, serves as a calcium sensor in vision. We report here the crystal structure of recombinant unmyristoylated recoverin at 1.9 A resolution. The four EF hands of the protein are arranged in a compact array that contrasts with the dumbbell shape of calmodulin and troponin C. A calcium ion is bound to EF hand 3, while EF hand 2 can bind samarium but not calcium in this crystal form. The other two EF hands have novel structural features that prevent or impair calcium binding. A concave hydrophobic surface formed by EF hands 1 and 2 may participate in the read out of calcium signals by recoverin and its homologs.

Amino Acid Sequence↗
PubMed1992

VILIP, a cognate protein of the retinal calcium binding proteins visinin and recoverin, is expressed in the developing chicken brain.

Using a selective cloning approach we previously isolated a number of cDNAs of transcripts that are newly expressed during terminal differentiation of the chicken optic tectum. Here, we have characterized one of these cDNAs (OZ1) by Northern analysis and in situ hybridization. The OZ1 cDNA hybridizes to two transcripts of 1.6 kb and 2.9 kb which are widely expressed in the brain but not detectable in liver, heart or skeletal muscle. Cloning of overlapping cDNAs revealed that both transcripts encode the same open reading frame for a polypeptide of 191 amino acids. The deduced protein contains 4 EF-hand consensus motifs characteristic of calmodulin-like Ca(2+)-binding proteins. It displays 40% and 46% sequence identity with the retinal photoreceptor-specific Ca(2+)-binding proteins visinin and recoverin, respectively, and was termed VILIP (visinin-like protein). VILIP transcripts are also expressed in the retina. However, the expression pattern does not overlap with that of visinin or recoverin. The possible functional implications of the similarity to recoverin, which regulates guanylate cyclase activity of retinal rod cells in a Ca(2+)-dependent manner, are discussed.

Animals↗
PubMed1993

The effect of recoverin-like calcium-binding proteins on the photoresponse of retinal rods.

The rod photoresponse is triggered by an enzyme cascade that stimulates cGMP hydrolysis. The resulting fall in cGMP leads to a decrease in Ca2+, which promotes photoresponse recovery by activating guanylate cyclase, causing cGMP resynthesis. In vitro biochemical studies suggest that Ca2+ activation of guanylate cyclase is medicated by recoverin, a 26 kd Ca(2+)-binding protein. To evaluate this, exogenous bovine recoverin and two other homologous Ca(2+)-binding proteins from chicken and Gecko retina were dialyzed into functionally intact Gecko rods using whole-cell recording. All three proteins prolonged the rising phase of the photoresponse without affecting the kinetics of response recovery. These results suggest that recoverin-like proteins affect termination of the transduction cascade, rather than mediate Ca(2+)-sensitive activation of guanylate cyclase.

Animals↗
PubMed2006

Anti-recoverin antibodies induce an increase in intracellular calcium, leading to apoptosis in retinal cells.

Autoantibodies against recoverin, a Ca2+-binding protein found in patients with cancer-associated retinopathy (CAR syndrome), penetrate retinal cells and induce their apoptosis via a mitochondrial pathway. The goal of this study was to investigate whether the entry of anti-recoverin antibody into E1A.NR3 retinal cells causes a change in intracellular Ca2+. Intracellular Ca2+ was measured using the Ca2+-sensitive fluorescent dye Fura-2 AM in living E1A.NR3 retinal cells treated with anti-recoverin antibody Rec-1, patients' autoantibodies, and control rat and human IgG. The exposure of retinal cells to Rec-1 antibody and to the CAR patients' autoantibodies in vitro caused a significant increase in intracellular Ca2+, while non-specific antibodies did not induce such an effect. Co-treatment of the E1A.NR3 cells with Rec-1 in the presence of nifedipine, a L-type Ca2+ channel blocker, significantly suppressed the increase of Ca2+. Treatment with nifedipine also blocked changes in the anti-apoptotic protein bcl-xL and in expressions of the pro-apoptotic protein bax. Nifedipine-treated cells also showed a decrease in cytosolic cytochrome c release and a decrease in caspase 3 activation, compared to cells treated only with Rec-1 antibody. The increase in the antibody-induced Ca2+ is at least in part dependent on extracellular Ca2+. Nifedipine was found to inhibit the entry of Ca2+ into the cells and to protect them from Rec-1-induced apoptosis. Increased levels of intracellular Ca2+ may lead to retinal dysfunction and degeneration in the CAR syndrome. Our results provide a molecular basis for the use of Ca2+ blockers in the treatment of the CAR syndrome.

Animals↗
PubMed1997

Rhodopsin phosphorylation in bovine rod outer segments is more sensitive to the inhibitory action of recoverin at the low rhodopsin bleaching than it is at the high bleaching.

Recoverin, a calcium-binding protein, is supposed to have rhodopsin kinase as a target in the retinal rod cell. In the present work, we show that efficiency of recoverin as an inhibitor of rhodopsin phosphorylation in bovine rod outer segments is inversely proportional to the level of rhodopsin bleaching. These results, together with the data obtained previously in a reconstituted system (Senin et al. (1997) Biochem. J. 321, 551-555), allow us to hypothesize that recoverin might be responsible for a Ca2(+)-dependent regulation of the kinase in vivo, preventing it from participating in the phosphorylation of unbleached rhodopsin.

Adenosine Triphosphate↗
PubMed1998

Obtaining and characterization of EF-hand mutants of recoverin.

Several EF-hand recoverin mutants were obtained and their abilities to bind to photoreceptor membranes and to inhibit rhodopsin kinase were determined. The mutants with the 'spoiled' 2nd, 3rd or (2nd+3rd) EF-hand structures did not act upon the kinase activity in the microM range of Ca2+ concentrations. Mutations of the 4th EF hand, which 'repaired' its Ca2+-binding activity, resulted in recoverin with three 'working' Ca2+-binding sites. The latter mutant inhibited rhodopsin kinase even more effectively than the wild-type recoverin, containing two working Ca2+-binding structures.

Animals↗
PubMed2000

[Point amino acid substitutions in Ca2+-binding centers of recoverin. III. Mutant with the fourth reconstructed Ca2+-binding site].

Unlike wild type recoverin with only two (the second and the third) functioning Ca(2+)-binding sites out of four potential ones, the +EF4 mutant contains a third active Ca(2+)-binding site. This site was reconstructed from the fourth potential Ca(2+)-binding domain by the introduction of several amino acid substitutions in it by site-directed mutagenesis. The effect of these mutations in the fourth potential Ca(2+)-binding site of myristoylated recoverin on the structural features and conformational stability of the protein was studied by fluorimetry and circular dichroism. The apoform of the resulting mutant (free of Ca2+ ions) was shown to have a higher calcium capacity, significantly lower thermal stability, and noticeably different secondary and tertiary structures as compared with the apoform of wild type recoverin.

Amino Acid Substitution↗
PubMed1993

Recoverin has S-modulin activity in frog rods.

In vertebrate photoreceptors, light induces hydrolysis of cGMP by activating cGMP phosphodiesterase (PDE), which results in closure of the cGMP-activated cation channel. During light adaptation, the cytoplasmic Ca2+ concentration decreases, and this decrease is one of the underlying mechanisms of light adaptation. Sensitivity-modulating protein (S-modulin) is a Ca(2+)-binding protein involved in light adaptation in frog rods; it regulates both the light sensitivity of PDE and the lifetime of activated PDE by controlling rhodopsin phosphorylation in a Ca(2+)-dependent manner. Recoverin has been reported as a Ca(2+)-dependent regulator of guanylate cyclase in bovine rods (Dizhoor, A. M., Ray, S., Kumar, S., Niemi, G., Spencer, M., Brolley, D., Walsh, K. A. Philipov, P. P., Hurley, J. B., and Stryer, L. (1991) Science 251, 915-918). Here, we show that recoverin has similar activity as S-modulin, and the amino acid sequences of both proteins are similar. The results strongly suggest that recoverin is bovine S-modulin and regulates PDE activation.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1997

Evaluation of the human gene encoding recoverin in patients with retinitis pigmentosa or an allied disease.

PURPOSE: To determine whether defects in the human recoverin gene cause retinitis pigmentosa (RP) or an allied disease such as Usher syndrome, Leber congenital amaurosis, or the Bardet-Biedl syndrome. METHODS: Single-strand conformation polymorphism analysis and direct genomic sequencing techniques were used to screen 596 unrelated patients, comprising 167 patients with dominant RP, 168 with recessive RP, and 261 with an allied disease. RESULTS: Four sequence variants were discovered. The first was a missense change (Ala200Thr) found in one family with autosomal dominant RP and in one family with autosomal recessive RP; it did not segregate with disease. The second was a silent, single-base variation affecting codon Ser24 with a minor allele frequency of approximately 0.5%. The third was a silent, single-base variation affecting codon Va1122. The fourth was a single-nucleotide substitution in intron 2, 11 bp upstream of exon 3. CONCLUSIONS: The authors found no evidence that mutations in the recoverin gene are a cause of RP or another of the hereditary retinal diseases studied. The human phenotype associated with mutations of the recoverin gene remains unknown.

Calcium-Binding Proteins↗
PubMedDate not supplied

Synaptic connectivity of two types of recoverin-labeled cone bipolar cells and glutamic acid decarboxylase immunoreactive amacrine cells in the inner plexiform layer of the rat retina.

We investigated the synaptic connectivity of two populations of recoverin-labeled bipolar cells and GABAergic neurons in the inner plexiform layer (IPL) of the rat retina. Two types of cone bipolar cells, type 2 and type 8, were stained with anti-recoverin antibodies, and GABAergic neurons were stained with anti-glutamic acid decarboxylase (GAD) antibodies. Type 2 cone bipolar axons received synaptic input from amacrine cell processes in 177 cases; among these amacrine cell processes, 92 processes (52.0%) were GAD-like immunoreactive. A total of 159 amacrine cell processes, which are presynaptic to type 8 cone bipolar cells, were observed. Among these processes, 117 processes (73.6%) were GAD-like immunoreactive. The postsynaptic elements at the ribbon synapses of recoverin-labeled cone bipolar cells were observed in 482 processes. In both type 2 and type 8 cone bipolar cells, the major output was to amacrine cell processes. At the ribbon synapses of the type 2 cone bipolar cells, 224 of the postsynaptic profiles were amacrine cell processes, 97 processes (43.3%) were GAD-like immunoreactive. In type 8 cone bipolar cells, 45 processes (30.2%) of 149 amacrine cell processes were GAD-like immunoreactive. Our results provide morphological evidence that GABA is a major transmitter involved in the visual processing of type 2 and 8 cone bipolar cells and GABA may have a stronger influence on type 8 cone bipolar cells than type 2 cone bipolar cells in the IPL of the rat retina.

Animals↗
PubMed2002

Recoverin and rhodopsin kinase.

The majority of proteins involved in vertebrate phototransduction are expressed specifically in photoreceptors. Recoverin and rhodopsin kinase are expressed primarily in retinal photoreceptors and they interact with each other in a Ca2+-dependent manner. This Ca2+-dependent interaction has been studied extensively in vitro. Experiments utilizing animal models and electrophysiological approaches have started to provide important insight regarding its invivo function. Recoverin can be viewed as a negative regulator of rhodopsin kinase in vertebrate phototransduction. This interaction imparts a negative feedback loop at the receptor level and may play an important role in light adaptation and in recovery.

Animals↗
PubMed1995

Distribution pattern of three neural calcium-binding proteins (NCS-1, VILIP and recoverin) in chicken, bovine and rat retina.

Neural Ca(2+)-binding proteins (NCaPs) constitute a subfamily of 4-EF-hand proteins, and display a histological and structural dichotomy: the A-type NCaPs are selectively expressed by the retina and pineal organ and display two canonical EF-hands, whereas the B-type NCaPs are found in the entire brain and present three regular EF-hands. In this study, antisera were raised against the A-type NCaP recoverin (26 kDa) and the B-type NCaPs VILIP and NCS-1 (22 kDa). Since the sequence identity among NCaPs is high, specific polyclonal antibodies were purified by double cross-immunoaffinity chromatography; both ELISA and immunoblot analyses determined that the resulting antibodies showed selectivity ratios inferior to 1/363 for the two other related NCaPs. Besides, the anti-VILIP antibodies displayed some affinity toward neurocalcin delta, and the antirecoverin antibodies recognized a 24 kDa protein, which is most likely visinin. Thus, immunohistochemical studies on the chicken, rat and cow retina revealed that anti-recoverin antibodies recognized the vertebrate photoreceptors and a small number of mammalian bipolar cells. Anti-VILIP antibodies exclusively labelled the inner retina, i.e. the amacrine and ganglion cells. NCS-1 was mainly present in the photoreceptor inner segments, the inner plexiform layer and the ganglion cells. NCS-1 showed the highest species disparity. The retinal localization of NCS-1 and VILIP offered an important morphological basis for the understanding of their function. Furthermore, specific antibodies against the NCaPs may enable the identification of cell populations in more complex neural tissues, such as the brain.

Animals↗
PubMed1994

Recoverin mediates the calcium effect upon rhodopsin phosphorylation and cGMP hydrolysis in bovine retina rod cells.

Rhodopsin phosphorylation and in consequence cGMP hydrolysis in bovine rod outer segments are Ca2+ dependent in the presence of ATP. The level of rhodopsin phosphorylation decreases and the lifetime of active phosphodiesterase increases when the free [Ca2+] is raised from < 1 nM to about 1 microM; in both cases the half-maximal effect was observed at 140-170 nM of free Ca2+. Antibodies to recoverin reverse both effects at high [Ca2+] but have no influence at low [Ca2+]. We conclude that the Ca2+ effects observed are mediated by recoverin which inhibits rhodopsin kinase at a high Ca2+ level.

Adenosine Triphosphate↗
PubMed1992

Isolation of human retinal genes: recoverin cDNA and gene.

A human retina cDNA library enriched for retina-specific clones was prepared by subtraction with a non-retina population of cDNA in combination with polymerase chain reaction (PCR) amplifications. A highly retina-specific cDNA clone (1190 bp) was obtained through this library encoding a 200 amino acid protein with three calcium binding sites and 87% homology to the bovine photoreceptor protein, recoverin, which has been shown to mediate the recovery of the dark current after photoactivation, and 58% homology to the calcium-binding chick cone protein, visinin. Analysis of the gene indicated a 9-10 kb single-copy gene with at least three exons and two introns. The three exons contained the entire coding sequence, and all of the calcium-binding EF-hand regions were in putative exon 1. The recoverin gene was mapped to human chromosome 17 by hybridization to a panel of human-rodent hybrid DNAs.

Amino Acid Sequence↗