Pinopsin is a chicken pineal photoreceptive molecule

  title={Pinopsin is a chicken pineal photoreceptive molecule},
  author={Toshiyuki Okano and Tỏru Yoshizawa and Yoshitaka Fukada},
IN avian pinealocytes, an environmental light signal resets the phase of the endogenous circadian pacemaker that controls the rhythmic production of melatonin1–6. Investigation of the pineal phototransduction pathway should therefore reveal the molecular mechanism of the biological clock. The presence of rhodopsin-Iike photoreceptive pigment4,5 7–9, transducin-like immunoreaction10, and cyclic GMP-dependent cation-channel activity11 in the avian pinealocytes suggests that there is a similarity… 

Molecular cloning of heterotrimeric G-protein α-subunits in chicken pineal gland

The bird pinealocytes show diagnostic characters which seem to represent an evolutionary transition from photosensory cells of lower vertebrates to the neuroendocrinal cells of mammals, and the G-proteins identified in the present study are likely to contribute to this neuroendocrine function of the chicken pineal cells.

Non-visual photoreception by a variety of vertebrate opsins.

The effort to identify the 'deep brain opsin' responsible for the photoperiodic gonadal response resulted in the identification of two kinds of opsins; pinopsin in the toad anterior preoptic nucleus and rhodopsIn in the pigeon lateral septum, which are localized in the cerebrospinal fluid-contacting neurons in the brain of the two animals.

Photoreception and circadian clock system of the chicken pineal gland

The recent characterization of the chick pineal clock genes strongly suggests that they constitute a transcription/translation‐based autoregulatory feedback loop, which is very similar to that generating circadian rhythmicity in mammalian SCN.

Light‐Dependent Expression of Pinopsin Gene in Chicken Pineal Gland

The mRNA level of pinopsin, a predominant photoreceptive molecule in the pineal gland, undergoes a diurnal fluctuation in chickens maintained on a light/dark cycle, demonstrating the presence of a feedback loop through which the light signal captured by Pinopsin stimulates the transcription of its own gene in the chicken pineal glands.

Developmental Expression Pattern of Phototransduction Components in Mammalian Pineal Implies a Light-Sensing Function

All of the components needed to reconstitute a functional phototransduction pathway are expressed in the majority of neonatal pinealocytes, although the expression levels of many of these genes decline dramatically during development, supporting the theory that the neonatal rat pineal itself is photosensitive.

Opsin-G11-Mediated Signaling Pathway for Photic Entrainment of the Chicken Pineal Circadian Clock

The results demonstrate the existence of a G11-mediated opsin-signaling pathway contributing to the photic entrainment of the circadian clock.

Rhythm and soul in the avian pineal

The ability to study entrainment, the oscillator itself, and a physiological output in the same tissue at the same time makes the avian pineal gland an excellent model to study the bases and regulation of circadian rhythms.

Immunoreactive pinopsin in pineal and retinal photoreceptors of various vertebrates.

The pineal organ of snakes and the parietal eye of reptiles equally failed to exhibit pinopsin immunoreactive photoreceptors, presumably, due to the absence of green-blue light-sensitive photoreceptor-type in these species.

Molecular Mechanisms of the Function of Pineal Organs

This chapter reviews the photopigments and the phototransduction pathways in the pineal organs of chicken, teleosts, and lamprey and those in the Pineal-related organ, the parietal eye, of lizard.



Rhodopsin-like photosensitivity of isolated chicken pineal gland

It is reported here that the action spectrum of the photosensitivity of the isolated chicken pineal resembles the absorption spectrum of rhodopsin, suggesting that the gland contains a photoreceptor.

A cyclic GMP-activated channel in dissociated cells of the chick pineal gland

The first recordings of cyclic GMP-activated channels in an extraretinal photoreceptor are reported, which may be essential for phototransduction in the chick pineal gland.

alpha-Transducin immunoreactivity in retinae and sensory pineal organs of adult vertebrates.

The possibility that the 43-kDa alpha transducin-immunopositive molecule present in the fish pineal organ and retina may be involved in phototransduction is raised.

Cone visual pigments are present in gecko rod cells.

It is found that the amino acid sequence of P521 deduced from the cDNA was very similar to that of iodopsin, respectively, which gives additional strength to the transmutation theory of Walls.

The pineal gland: a biological clock in vitro.

Circadian rhythmicity was studied by following the course of N-acetyl-transferase activity in the pineal glands of chickens in vitro. The results indicate (i) a daily change during day 1 of organ