• Genomics & Informatics
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• 제19권1호
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• pp.9.1-9.5
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• 2021

Mammalian olfactory receptors are a family of G protein-coupled receptors (GPCRs) that occupy a large part of the genome. In human genes, olfactory receptors account for more than 40% of all GPCRs. Several types of GPCR structures have been identified, but there is no single olfactory receptor whose structure has been determined experimentally to date. The aim of this study was to model the interactions between an olfactory receptor and its ligands at the molecular level to provide hints on the binding modes between the OR2W1 olfactory receptor and its agonists and inverse agonists. The results demonstrated the modes of ligand binding in a three-dimensional model of OR2W1 and showed a statistically significant difference in binding affinity to the olfactory receptor between agonists and inverse agonists.

• Genomics & Informatics
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• 제19권2호
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• pp.18.1-18.8
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• 2021

G protein–coupled receptors (GPCRs), including olfactory receptors, account for the largest group of genes in the human genome and occupy a very important position in signaling systems. Although olfactory receptors, which belong to the broader category of GPCRs, play an important role in monitoring the organism's surroundings, their actual three-dimensional structure has not yet been determined. Therefore, the specific details of the molecular interactions between the receptor and the ligand remain unclear. In this report, the interactions between human olfactory receptor 1A1 and its odorant molecules were simulated using computational methods, and we explored how the chemically simple odorant molecules activate the olfactory receptor.

• Applied Microscopy
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• 제37권4호
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• pp.219-230
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• 2007

마우스의 코 안으로 5% $ZnSO_4$용액을 점적하는 것이 코중격 후각상피에 미치는 영향과, 그 이후 후각수용세포가 재생되는 과정을 주사전자현미경과 투과전자현미경을 사용하여 형태학적으로 조사하였고, 그 결과는 다음과 같다. 1. 5% $ZnSO_4$용액을 점적한 후 6시간에서 24시간 사이에 코중격 후각상피층은 일부의 기저세포들을 제외하고는 완전하게 탈락되었다. 2. $ZnSO_4$처리 후 3일군에서는 코중격 후각상피세포들 중 부분적으로 남아 있던 기저세포들의 세포분열로 형성된 새로운 후각상피세포들로 후각상피층은 2층으로 나타났다. 또한 새롭게 형성된 후각상피세포들의 상부 세포막에는 미세응모가 돌출되었다. 3. 5% $ZnSO_4$용액을 점적하고 5일이 경과된 코중격 후각수용세포들에서는 다수의 중심소체와 기저소체가 관찰되었고, 상부 세포막에는 미세응모들 사이에 섬모들이 줄지어 나타났다. 또한 새롭게 형성된 코중격 후각수용세포들에서 처음으로 후각소포의 초기 형태가 나타났으며, 1주가 경과된 후각상피층에는 전형적인 형태의 후각소포를 관찰할 수 있었다. 4. 5% $ZnSO_4$용액 점적 후 2주가 경과된 경우, 성숙한 형태의 후각소포를 가지고 있는 후각수용세포가 관찰되었다. 이와 같은 결과는 5% $ZnSO_4$용액의 처리가 마우스 코중격의 후각상피층을 완전하게 박리시킬 수 있으므로 포유류 신경조직의 재생연구를 위해 유용한 실험적 모델임을 뒷받침한다, 또한 새롭게 재생되는 후각수용세포의 상부 세포막이 처음에는 미세응모로 표면적을 넓히고, 시간이 경과함에 따라 일렬로 배열된 섬모들로 대치되며, 그 후 섬모를 포함한 상부세포막이 부분적으로 돌출하고, 마지막으로 전형적인 후각소포로 발달한다.

• Genomics & Informatics
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• 제16권1호
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• pp.2-9
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• 2018

Olfactory receptors (ORs) in mammals are generally considered to function as chemosensors in the olfactory organs of animals. They are membrane proteins that traverse the cytoplasmic membrane seven times and work generally by coupling to heterotrimeric G protein. The OR is a G protein-coupled receptor that binds the guanine nucleotide-binding $G{\alpha}_{olf}$ subunit and the $G{\beta}{\gamma}$ dimer to recognize a wide spectrum of organic compounds in accordance with its cognate ligand. Mammalian ORs were originally identified from the olfactory epithelium of rat. However, it has been recently reported that the expression of ORs is not limited to the olfactory organ. In recent decades, they have been found to be expressed in diverse organs or tissues and even tumors in mammals. In this review, the expression and expected function of olfactory receptors that exist throughout an organism's system are discussed.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.928-933
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• 2007

Cameleon is a genetically engineered $Ca^{2+}$ sensing molecule consisting of two variants of the green fluorescent protein (GFP), calmodulin and calmodulin-binding protein, M13. HEK-293 cells stably expressing three types of cameleons, yellow cameleon-2, cameleon-3er, and cameleon-2nu, were constructed, and the expression and localization of these cameleons were confirmed by fluorescent imaging. Among the cameleons, the yellow cameleon-2 was selected for analyzing the change in $Ca^{2+}$ induced by the olfactory receptor-mediated signal transduction, because it is localized in the cytosol and binds to cytosolic $Ca^{2+}$ ions. Cells stably expressing yellow cameleon-2 were transfected with each of the test olfactory receptor genes, odr-10 and 17, and the expression of the olfactory receptor genes were examined using immunocytochenmical methods and RT-PCR. Stimulating each olfactory receptor with its specific odorant caused an increase in the intracellular $Ca^{2+}$ level, which was measured using yellow cameleon-2. These results demonstrate that yellow cameleon-2 can be conveniently used to examine the function of the olfactory receptors expressed in heterologous cells.

• 한국어류학회지
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• 제28권1호
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• pp.28-34
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• 2016

한국산 날개망둑 Favonigobius gymnauchen 후각기관은 2015년 7월과 8월 사이 전라북도 부안군 변산면 격포리의 조간대에서 채집된 개체들을 대상으로 실체현미경, 광학현미경 그리고 주사전자현미경을 이용하여 해부학 및 조직학적 특징들을 조사하였다. 후각기관은 두부 주둥이 위 좌우로 한 쌍이 존재하며, 전비공과 후비공, 한개의 비강, 두 개의 비낭, 후신경, 그리고 후구로 구성되었다. 비강 내 감각상피는 연결성 유형의 분포를 보였으며, 섬모성 감각세포만을 가지고 있었고, 감각세포, 지지세포, 기저세포들로 구성되었다. 비감각상피는 층상상피세포들로 구성되었으며, 표면에 많은 점액공을 가지고 있었다. 따라서 이러한 후각기관의 특징들은 연안지역 조수 웅덩이와 수심이 얕은 조간대의 생태적 서식처와 밀접한 관계가 있는 것으로 여겨진다.

• Applied Microscopy
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• 제50권
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• pp.18.1-18.7
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• 2020

The olfactory anatomy and histology of Lethenteron reissneri were researched using a stereo microscope, a light microscope, and a scanning electron microscope. As in other lampreys, it shows same characters as follows: i) a single olfactory organ, ii) a single tubular nostril, iii) a single olfactory chamber with gourd-like form, iv) a nasal valve, v) a nasopharyngeal pouch, vi) a sensory epithelium (SE) of continuous distribution, vii) a supporting cells with numerous long cilia, viii) an accessory olfactory organ. However, the description of a pseudostratified columnar layer in the SE and Non SE is a first record, not reported in sea lamprey Petromyzon marinus. In particular, both 19 to 20 lamellae in number and olfactory receptor neuron's quarter ciliary length of the knob diameter differ from those of P. marinus. From these results, it might be considered that the olfactory organ of L. reissneri shows well adaptive structure of a primitive fish to slow flowing water with gravel, pebbles, and sand and a hiding habit into sand bottom at daytime. The lamellar number and neuron's ciliary length may be a meaningful taxonomic character for the class Petromyzonida.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.639-642
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• 2003

본 연구는 후각 수용 단백질인 ODR10를 GST와 Histidine tag를 각각 N 말단과 C 말단에 삽입한 후 두 가지의 발현 벡터에 넣어 대장균에서 발현시켰다. 부분 정제된 단백질을 QCM의 수정진동자에 코팅한 후 여러 종류의 냄새 분자와의 상호 작용을 관찰하였다. 발현양은 적었지만 QCM실험 결과 발현된 단백질이 diacetyl과 반응한다는 것을 알 수 있었다. ODR10 단백질과 diacetyl의 결합 정도는 다른 냄새 분자와 비교했을 때 $5{\sim}10$배 정도 차이가 났으며 이를 통해 후각 수용 단백질을 발현시킨 대장균 세포들을 후각센서를 개발하는데 사용할 수 있다는 것을 알 수 있었다. 또한 현재까지는 1000가지 이상 존재한다고 알려진 후각 수용 단백질들이 어떤 냄새 분자와 특이적인 결합성을 가지는지 조사하기 위해서는 복잡하고 시간이 오래 걸리는 실험을 해야 했었지만, 대장균에서 발현시키는 시스템을 통해 경제적이고 효율적으로 조사를 할 수 있게 되었다.

• Applied Microscopy
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• 제48권1호
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• pp.11-16
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• 2018

For Odontamblyopus lacepedii with small and turbid eyes, the gross structure and histology of the olfactory organ, which is important for its survival and protection of the receptor neuron in estuarial environment and its ecological habit, was investigated using a stereo, light and scanning electron microscopes. Externally, the paired olfactory organs with two nostrils are located identically on each side of the snout. These nostrils are positioned at the anterior tip of the upper lip (anterior nostril) and just below eyes covered with the epidermis (posterior nostril). Internally, this is built of an elongated olfactory chamber and two accessory nasal sacs. In histology, the olfactory chamber is elliptical in shape, and lined by the sensory epithelium and the non-sensory epithelium. The sensory epithelium of a pseudostratified layer consists of olfactory receptor neurons, supporting cells, basal cells and lymphatic cells. The non-sensory epithelium of a stratified layer has swollen stratified epithelial cells and mucous cells with acidic and neutral sulfomucin. From these results, we confirmed the olfactory organ of O. lacepedii is adapted to its ecological habit as well as its habitat with burrows at the muddy field with standing and murky waters.

• BMB Reports
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• 제45권11호
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• pp.612-622
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• 2012

Olfactory receptors (ORs) detect volatile chemicals that lead to the initial perception of smell in the brain. The olfactory receptor (OR) is the first protein that recognizes odorants in the olfactory signal pathway and it is present in over 1,000 genes in mice. It is also the largest member of the G protein-coupled receptors (GPCRs). Most ORs are extensively expressed in the nasal olfactory epithelium where they perform the appropriate physiological functions that fit their location. However, recent whole-genome sequencing shows that ORs have been found outside of the olfactory system, suggesting that ORs may play an important role in the ectopic expression of non-chemosensory tissues. The ectopic expressions of ORs and their physiological functions have attracted more attention recently since MOR23 and testicular hOR17-4 have been found to be involved in skeletal muscle development, regeneration, and human sperm chemotaxis, respectively. When identifying additional expression profiles and functions of ORs in non-olfactory tissues, there are limitations posed by the small number of antibodies available for similar OR genes. This review presents the results of a research series that identifies ectopic expressions and functions of ORs in non-chemosensory tissues to provide insight into future research directions.