FB2020_06, released Dec 22, 2020
Gene: Dmel\ninaE
FB2020_06, released Dec 22, 2020
Gene: Dmel\ninaE
Gene: Dmel\ninaE
Gene: Dmel\ninaE
Rh1, rhodopsin, Rhodopsin 1, Rhodopsin-1, Rh-1
rhodopsin expressed in photoreceptors R1-R6, response to light intensity, phototransduction, thermotaxis
Please see the JBrowse view of Dmel\ninaE for information on other features
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Gene model reviewed during 5.40
Gene model reviewed during 5.54
Low-frequency RNA-Seq exon junction(s) not annotated.
1.7 (northern blot)
There is only one protein coding transcript and one polypeptide associated with this gene
33 (kD)
373 (aa); 41 (kD predicted)
Phosphorylated on some or all of the serine and threonine residues present in the C-terminal region.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\ninaE using the Feature Mapper tool.
Eye-enriched transcripts determined by ratio of expression level in wild-type heads. versus expression level in so heads.
ninaE transcripts are present at near wild type levels in ninaEΔAsn20 mutants.
Comment: 69-100h APF
Comment: 85-95h APF
Comment: 72-100h APF. Immature protein (40kDa) also present at a low level.
GBrowse - Visual display of RNA-Seq signals
View Dmel\ninaE in GBrowse 23-67
Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
polyclonal
Source for identity of: ninaE CG4550
ninaE is required in
mid third-instar larvae, but not in late third-instar larvae, for normal thermal preference in a temperature gradient.
ninaE is important for circadian photoentrainment to green and yellow light.
ninaE maturation defects induce photoreceptor death by apoptosis.
Identified with: GH11778.5prime <up>FlyBase curator comment: EST subsequently found to be chimeric</up>.
In disrupted photoreceptor cells metarhodopsin is not stabilised until arrestin is present. In intact photoreceptor cels significant metarhodopsin stabilisation occurs even in the absence of bound arrestin.
Light driven release of arrestin from ninaE in the visual cycle is studied using immunochemical and spectroscopic probes of in vitro regenerated wild type and mutant ninaE. Experiments identify the spectroscopic transitions and arrestin release/binding as separate events that can be decoupled from each other.
Retinoid (vitamin A) deprivation reduces transcription of ninaE and this increases on carrot juice feeding. Deprivation by feeding on yeast-glucose medium reduces ninaE protein, but not mRNA.
Vitamin A deprivation causes a reduction in the steady state levels of rhodopsin 1 (ninaE) mRNA and protein; levels recover on feeding vitamin A.
Retinal degeneration results from interference in the maturation of wild type rhodopsin by mutant ninaE proteins.
The collapse of rhabdomere morphogenesis in null mutants suggest the ninaE protein plays a significant structural role in photosensitive membrane development.
ninaE mutants act as dominant rhodopsin mutants by suppressing the production of the wild type ninaE rhodopsin. As a consequence of the lowered rhodopsin content the mutations suppress the rapid retinal degeneration associated with rdgC and norpA mutations. Independent of this phenotype the dominant mutations also induce slower photoreceptor generation in the absence of other photoreceptor mutations.
Light absorption by rhodopsin generates metarhodopsin which activates heterotrimeric G proteins in photoreceptor cells. ninaE is thermally stable, this is a consequence of its interaction with Arr1. Light absorption by ninaE initially regenerated an inactive rhodopsin-like intermediate which is subsequently converted in the dark to active rhodopsin. The accumulation of inactive rhodopsin at higher light levels may represent a mechanism for gain regulation in the visual cycle.
Light induces a rapid increase in internal calcium concentration in photoreceptors. Detectable calcium signals can be observed in mutants.
A 38bp fragment of the ninaE promoter includes a binding site for the gl product and is restricted in its ability to activate a heterologous promoter in response to gl expression. A 29bp truncated version of the same binding site directs unrestricted expression in response to gl. The restriction is mediated by a protein binding an ATTG repeat present near the gl binding site.
Major opsin genes can be transcribed in the absence of carotenoid, or retinoid. Expression of mature opsin is extremely depressed by carotenoid deprivation. The chromophore 11-cis-3-hydroxyretinal accelerates the synthesis of opsin by inducing its maturation.
ninaE promoter used to drive expression of Rh2, Rh3 and Rh4 in R1-6 photoreceptors. Transgenic flies expressing both ninaE (Rh1) and Rh2 in photoreceptors R1-6 demonstrate response that indicates that photoreceptors trigger receptor potentials tuned to combined spectral response of both rhodopsins.
Degeneration of R1-6 photoreceptors was studied in ninaE mutants: the time course of degeneration is allele-dependent. Degeneration is independent of illumination cycle to which the animals are exposed, or presence of screening pigments in the eye. Eventually the effect extends to R7 and R8.
Mutant analysis showed that the N-linked glycosylation site plays a critical role in the maturation of rhodopsin.
Amount of ninaE (Rh1) protein assayed in Western blots with monoclonal antibody was determined for a series of ninaA mutant alleles.
ninaE protein distribution in the photoreceptor cells has been studied using electron microscopy.
Identified as a cDNA clone that is expressed exclusively or predominantly in the adult visual system.
ninaE,rdgC double mutant combinations demonstrate that rhodopsin is required to trigger retinal degeneration in rdgC flies.
ninaE has been isolated and characterized to reveal that the ninaE gene product belongs to the family of opsin proteins.
In one clean use of a ninaE variant to eliminate responses of R1-6 photoreceptors, turn-on of per gene expression in nuclei of such cells (which requires exposures of the flies to light-dark transitions) was normal in ninaE17 (Zerr, Hall, Rosbash and Siwicki, 1990). A number of studies of this general sort have been carried out on the double mutant, ort ninaE (recovered as "oraJK84"); ort by itself is known to cause deficits in ERG light-on and light-off transient spikes (O'Tousa, Leonard and Pak, 1989). The application of 'ora' have usually been aimed at using it as a R1-6-removing tool for behavioral (e.g., Coombe, 1984) or physiological (e.g., Stark, Schilly, Christianson, Bone and Landrum, 1990) experiments. Many of the abnormalities, such as assessments of visual pigment content (most classically, Harris, Stark and Walker, 1976) are probably attributable to the ninaE component only; this includes an explicit demonstration that rhabdomere degeneration (Stark and Sapp, 1987) is caused by ninaE (O'Tousa, Leonard and Pak, 1989), similar to that caused by any other severe ninaE mutation. But certain effects of 'ora' on visually mediated behaviors, such as decrements in male courtship (Markow and Manning, 1980), the absence of blue-light influenced phototaxis (Willmund and Fischbach, 1977), or the absence of R1-6-dependent optomotor responses (Heisenberg and Buchner, 1977) could be affected by both factors.
ninaE+ encodes the opsin moiety of the major rhodopsin, RH1, which occupies the rhabdomeres of the outer six photoreceptor cells R1-R6 in each ommatidium of the adult fly. This rhodopsin is also expressed in the larval light sensitive organs (Zucker, Cowman and Rubin, 1985; Pollack and Benzer, 1988). RH1 is a 39kD basic protein (Nichols and Pak, 1985). Homozygous ninaE mutants display severe depletion of rhodopsin from the outer photoreceptors, shown microspectrophotometrically and physiologically (Scavarda, O'Tousa and Pak, 1983; Johnson and Pak, 1986), as well as by absence of R1-6 staining with an anti-(Drosophila)rhodopsin MAb (de Couet and Tanimura, 1987). Electroretinograms demonstrate that the prolonged depolarizing afterpotential (PDA) is absent; also, the sustained corneal-negative light-coincident response is reduced in some alleles and nearly wild type in amplitude in others. Physiological measurements of light-induced 'quantum bumps' in three ninaE mutants (whose RH1 decrements range from 10-2 to 10-6 of wild-type) indicate that these responses-at the level of a given bump-are basically normal (implying that interactions among rhodopsin molecules are not likely to be critical for generation and adaptation of these 'basic units' of photoreceptor potential (Johnson and Pak, 1986); bump amplitudes were higher than normal (more so in the more severe of the three mutants). Increased and decreased dosages of ninaE+ cause higher than normal and lower than normal rhodopsin levels (Scavarda, O'Tousa and Pak, 1983). Some mutants, when heterozygous to wild type, show less than 50% of the normal rhodopsin level (e.g., ninaE7/+ yields 35% of the normal level); in heterozygotes of ninaE5, ninaE6, and ninaE7, the basic photoreceptor potential, as seen in electroretinograms, may be reduced. In mutant homozygotes, the cross-sectional area of rhabdomeres 1-6 is smaller than normal; in some mutants (ninaE1, ninaE3, ninaE7 and ninaE8), an age-dependent, light-independent degeneration of R1-6 rhabdomeres (but not cell bodies) is observed; in the case of severe alleles like ninaE1 (see other information) or ninaE17, the rhabdomeres are present at eclosion, but degenerate rapidly thereafter (e.g., Stark and Sapp, 1987; O'Tousa, Leonard and Pak, 1989); degeneration is cell autonomous in mosaics (Stark, Srygley and Greenberg, 1981).
