• Title/Summary/Keyword: Molecular motor

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Two cases of spinal muscular atrophy type 1 with extensive involvement of sensory nerves (광범위한 감각신경 침범을 동반한 척수성 근위축증 2예)

  • Lee, Ran;Chung, Sochung;Koh, Sung-Eun;Lee, In Kyu;Lee, Jongmin
    • Clinical and Experimental Pediatrics
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    • v.51 no.12
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    • pp.1350-1354
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    • 2008
  • Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by diffuse proximal and distal weakness due to deletion of the survival motor neuron (SMN) gene localized on chromosome 5 (5q11.2-13.3). SMA has been considered as a pure lower motor neuron disorder, and a definitive diagnosis can be established by molecular genetic testing. Here, we describe two patients with severe hypotonia and frequent aspirations at early infancy. Nerve conduction studies showed more extensive sensory involvement in these patients diagnosed to have SMA by genetic study than in classical cases of SMA. To the best of our knowledge, this is the first report of SMA Type 1 with sensory nerve involvement in Korea.

Specific kinesin and dynein molecules participate in the unconventional protein secretion of transmembrane proteins

  • Sung Ho Eun;Shin Hye Noh;Min Goo Lee
    • The Korean Journal of Physiology and Pharmacology
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    • v.28 no.5
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    • pp.435-447
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    • 2024
  • Secretory proteins, including plasma membrane proteins, are generally known to be transported to the plasma membrane through the endoplasmic reticulum-to-Golgi pathway. However, recent studies have revealed that several plasma membrane proteins and cytosolic proteins lacking a signal peptide are released via an unconventional protein secretion (UcPS) route, bypassing the Golgi during their journey to the cell surface. For instance, transmembrane proteins such as the misfolded cystic fibrosis transmembrane conductance regulator (CFTR) protein and the Spike protein of coronaviruses have been observed to reach the cell surface through a UcPS pathway under cell stress conditions. Nevertheless, the precise mechanisms of the UcPS pathway, particularly the molecular machineries involving cytosolic motor proteins, remain largely unknown. In this study, we identified specific kinesins, namely KIF1A and KIF5A, along with cytoplasmic dynein, as critical players in the unconventional trafficking of CFTR and the SARS-CoV-2 Spike protein. Gene silencing results demonstrated that knockdown of KIF1A, KIF5A, and the KIF-associated adaptor protein SKIP, FYCO1 significantly reduced the UcPS of △F508-CFTR. Moreover, gene silencing of these motor proteins impeded the UcPS of the SARS-CoV-2 Spike protein. However, the same gene silencing did not affect the conventional Golgi-mediated cell surface trafficking of wild-type CFTR and Spike protein. These findings suggest that specific motor proteins, distinct from those involved in conventional trafficking, are implicated in the stress-induced UcPS of transmembrane proteins.

A Novel Pyrazolo[3,4-d]pyrimidine Induces Heme Oxygenase-1 and Exerts Anti-Inflammatory and Neuroprotective Effects

  • Lee, Ji Ae;Kwon, Young-Won;Kim, Hye Ri;Shin, Nari;Son, Hyo Jin;Cheong, Chan Seong;Kim, Dong Jin;Hwang, Onyou
    • Molecules and Cells
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    • v.45 no.3
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    • pp.134-147
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    • 2022
  • The anti-oxidant enzyme heme oxygenase-1 (HO-1) is known to exert anti-inflammatory effects. From a library of pyrazolo[3,4-d]pyrimidines, we identified a novel compound KKC080096 that upregulated HO-1 at the mRNA and protein levels in microglial BV-2 cells. KKC080096 exhibited anti-inflammatory effects via suppressing nitric oxide, interleukin1β (IL-1β), and iNOS production in lipopolysaccharide (LPS)-challenged cells. It inhibited the phosphorylation of IKK and MAP kinases (p38, JNK, ERK), which trigger inflammatory signaling, and whose activities are inhibited by HO-1. Further, KKC080096 upregulated anti-inflammatory marker (Arg1, YM1, CD206, IL-10, transforming growth factor-β [TGF-β]) expression. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridinetreated mice, KKC080096 lowered microglial activation, protected the nigral dopaminergic neurons, and nigral damage-associated motor deficits. Next, we elucidated the mechanisms by which KKC080096 upregulated HO-1. KKC080096 induced the phosphorylation of AMPK and its known upstream kinases LKB1 and CaMKKbeta, and pharmacological inhibition of AMPK activity reduced the effects of KKC080096 on HO-1 expression and LPS-induced NO generation, suggesting that KKC080096-induced HO-1 upregulation involves LKB1/AMPK and CaMKKbeta/AMPK pathway activation. Further, KKC080096 caused an increase in cellular Nrf2 level, bound to Keap1 (Nrf2 inhibitor protein) with high affinity, and blocked Keap1-Nrf2 interaction. This Nrf2 activation resulted in concurrent induction of HO-1 and other Nrf2-targeted antioxidant enzymes in BV-2 and in dopaminergic CATH.a cells. These results indicate that KKC080096 is a potential therapeutic for oxidative stress-and inflammation-related neurodegenerative disorders such as Parkinson's disease.

Endochondral Ossification Signals in Cartilage Degradation During Osteoarthritis Progression in Experimental Mouse Models

  • Kawaguchi, Hiroshi
    • Molecules and Cells
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    • v.25 no.1
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    • pp.1-6
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    • 2008
  • Osteoarthritis (OA), one of the most common skeletal disorders characterized by cartilage degradation and osteophyte formation in joints, is induced by accumulated mechanical stress; however, little is known about the underlying molecular mechanism. Several experimental OA models in mice by producing instability in the knee joints have been developed to apply approaches from mouse genetics. Although proteinases like matrix metalloproteinases and aggrecanases have now been proven to be the principal initiators of OA progression, clinical trials of proteinase inhibitors have not been successful for the treatment, turning the interest of researchers to the upstream signals of proteinase induction. These signals include undegraded and fragmented matrix proteins like type II collagen or fibronection that affects chondrocytes through distinct receptors. Another signal is proinflammatory factors that are produced by chondrocytes and synovial cells; however, recent studies that used mouse OA models in knockout mice did not support that these factors have a role in the central contribution to OA development. Our mouse genetic approaches found that the induction of a transcriptional activator Runx2 in chondrocytes under mechanical stress contributes to the pathogenesis of OA through chondrocyte hypertrophy. In addition, chondrocyte apoptosis has recently been identified as being involved in OA progression. We hereby propose that these endochondral ossification signals may be important for the OA progression, suggesting that the related molecules can clinically be therapeutic targets of this disease.

In silico discovery and evaluation of phytochemicals binding mechanism against human catechol-O-methyltransferase as a putative bioenhancer of L-DOPA therapy in Parkinson disease

  • Rath, Surya Narayan;Jena, Lingaraja;Bhuyan, Rajabrata;Mahanandia, Nimai Charan;Patri, Manorama
    • Genomics & Informatics
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    • v.19 no.1
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    • pp.7.1-7.13
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    • 2021
  • Levodopa (L-DOPA) therapy is normally practised to treat motor pattern associated with Parkinson disease (PD). Additionally, several inhibitory drugs such as Entacapone and Opicapone are also cosupplemented to protect peripheral inactivation of exogenous L-DOPA (~80%) that occurs due to metabolic activity of the enzyme catechol-O-methyltransferase (COMT). Although, both Entacapone and Opicapone have U.S. Food and Drug Administration approval but regular use of these drugs is associated with high risk of side effects. Thus, authors have focused on in silico discovery of phytochemicals and evaluation of their effectiveness against human soluble COMT using virtual screening, molecular docking, drug-like property prediction, generation of pharmacophoric property, and molecular dynamics simulation. Overall, study proposed, nine phytochemicals (withaphysalin D, withaphysalin N, withaferin A, withacnistin, withaphysalin C, withaphysalin O, withanolide B, withasomnine, and withaphysalin F) of plant Withania somnifera have strong binding efficiency against human COMT in comparison to both of the drugs i.e., Opicapone and Entacapone, thus may be used as putative bioenhancer in L-DOPA therapy. The present study needs further experimental validation to be used as an adjuvant in PD treatment.

Molecular Identification and Expression of Myosin Light Chain in Shortspine Spurdog (Squalus mitsukurii)

  • Kim, Soo Cheol;Sumi, Kanij Rukshana;Sharker, Md Rajib;Kho, Kang Hee
    • Journal of Marine Life Science
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    • v.3 no.1
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    • pp.1-8
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    • 2018
  • Myosin is considered as the vital motor protein in vertebrates and invertebrates. Our present study was conducted to decipher the occurrence of myosin in dog fish (Squalus mitsukurii). We isolated one clone containing 979 bp cDNA sequence, which consisted of a complete coding sequence of 453 bp and a deduced amino acid sequence of 150 amino acids from the open reading frame with molecular weight, isoelectric point and aliphatic index are 16.72 Kda, 4.49 and 78.00, respectively. It contained 428 bp long 3' UTR with single potential polyadenylation signals (AATAAA). The predicted EF CA2+ binding domains were identified in residue 6-41, 83-118 and 133-150. A BLAST search indicates this protein exhibits a strong similarity to whale shark (Rhincodon typus) MLC3 (91% identical) and also house mouse (Mus musculus) MLC isoform 3f (81% identical). Phylogenetic analysis revealed that this protein is a MLC 3 isoform like protein. This protein also demonstrates highly conserved region with other myosin proteins. Homology modeling of S. mitsukuri was performed using crystal structure of Gallus gallus skeletal muscle myosin II based on high similarity. Reverse transcription-polymerase chain reaction (PCR), quantitative PCR results exhibits dogfish myosin protein is highly expressed in muscle tissue.

Interaction of CLIP-170, a Regulator of Microtubule Plus End Dynamics, with Kinesin 1 via KIF5s (미세소관의 plus end dynamics를 조절하는 CLIP-170과 kinesin 1의 KIF5s를 통한 결합)

  • Jang, Won Hee;Jeong, Young Joo;Lee, Won Hee;Kim, Mooseong;Kim, Sang-Jin;Urm, Sang-Hwa;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.27 no.6
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    • pp.673-679
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    • 2017
  • Microtubules are long rods in the cytoplasm of cells that plays a role in cell motility and intracellular transport. Microtubule-based transport by motor proteins is essential in intracellular transport. Kinesin 1 is a molecular motor protein that mediates the intracellular transport of various membranous vesicles, mRNAs, and proteins along microtubules. It is comprised of two heavy chains (KHCs, also called KIF5s) and two light chains (KLCs). KIF5s bear a motor domain in their amino (N)-terminal regions and interact with various cargoes through the cargo-binding domain in their carboxyl (C)-terminal regions. To identify proteins interacting with KIF5B, yeast two-hybrid screening was performed, and a specific interaction with the cytoplasmic linker protein 170 (CLIP-170), a plus end microtubule-binding protein, was found. The coiled-coil domain of CLIP-170 is essential for interactions with KIF5B in the yeast two-hybrid assay. CLIP-170 bound to the cargo-binding domain of KIF5B. Also, other KIF5s, KIF5A and KIF5C, interacted with CLIP-170 in the yeast two-hybrid assay. In addition, glutathione S-transferase (GST) pull-downs showed that KIF5s specifically interacted with CLIP-170. An antibody to KIF5B specifically co-immunoprecipitated CLIP-170 associated with KIF5B from mouse brain extracts. These results suggest that kinesin 1 motor protein may transport CLIP-170 in cells.

The Regulation Mechanisms of Kinesin Motor Proteins (Kinesin 모터 단백질의 조절 기전)

  • Park, Sang Jun;Seog, Joung-Su;Moon, Il Soo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.27 no.7
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    • pp.840-848
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    • 2017
  • Proper intracellular transport is essential for normal cell function. Intracellular transport is mediated by microtubule-dependent molecular motor proteins, as well as kinesin and cytoplasmic dynein, which move their cargo along long, microtubule tracks in cells. Kinesins are ATP-dependent plus-end-directed motor proteins in the intracellular transport of organelles, vesicles, RNA complexes, and protein complexes. The mislocalization of these different types of cargo has been linked to cell dysfunction and degeneration. The cargo transport of kinesins can be described by the following steps: binding to the appropriate cargo and/or adaptor proteins, activation of the kinesin's motility and movement along the microtubule, and the release of the cargo at the correct destination. Recently, several studies have revealed the mechanisms for the regulation of kinesin motor activity, including cargo loading and unloading. Intracellular cargo transport is also modulated by adaptor proteins, which link the kinesins to their cargo. The regulatory proteins, which include protein kinases and phosphatases, regulate kinesin motor activity directly through the phosphorylation or dephosphorylation of kinesins and indirectly through the modification of adaptor proteins, such as c-Jun NH-terminal kinase-interacting proteins, or of the microtubule network. These findings lay the groundwork for understanding how kinesins are differentially engaged in intracellular cargo transport. In addition, understanding the regulatory mechanisms of each kinesin is an area of key interest within cell biology and neurophysiology. In this study, we reviewed kinesins' regulation proteins and discuss how their regulation affects cargo recognition and transport.

Comparison of Plant-derived Carbonaceous Components (Organic Molecular Markers and 14carbon) in PM2.5 in Summer and Autumn at Kazo, Japan

  • Sasaka, Kouki;Wang, Qingyue;Sakamoto, Kazuhiko
    • Asian Journal of Atmospheric Environment
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    • v.11 no.3
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    • pp.165-175
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    • 2017
  • In Japan, the primary carbonaceous particles emitted from motor vehicles and waste incinerators have been reduced due to strict regulations against exhaust gas. However, the relative contribution of carbonaceous particles derived from plants and biomass has been increasing. Accordingly, compositional analysis of carbonaceous particles has become increasingly important to determine the sources and types of particles produced. To reveal the sources of the organic particles contained in particulate matter with diameters of ${\leq}2.5{\mu}m$ ($PM_{2.5}$) and the processes involved in their generation, we analyzed molecular marker compounds (2-methyltetrols, cis-pinonic acid, and levoglucosan) derived from the plants and biomass in the $PM_{2.5}$ collected during daytime- and nighttime-sampling periods in summer (July and August) and autumn (November) in Kazo, which is in the northern area of Saitama prefecture, Japan. We also measured $^{14}C$ carbonaceous concentrations in the same $PM_{2.5}$ samples. The concentrations of 2-methyltetrols were higher in the summer than in the autumn. Because the deciduous period overlaps with this decrease in the levels of 2-methyltetrols, we considered the emission source to broad-leaved trees. In contrast, the emission source of the cis-pinonic acid precursor was considered to be conifers, because its concentration remained almost constant throughout the year. The concentration of levoglucosan was considerably increased in the autumn due to frequent biomass open burning. The ratio of plant-derived carbon to total carbon, obtained by measuring of $^{14}C$, in summer $PM_{2.5}$ sample was higher in the nighttime, and could be influenced by anthropogenic sources during the daytime.

Analysis for Compatibility of Gyejibongnyeong-hwan and Its Biological Activities (계지복령환(桂枝茯苓丸)의 배오(配伍)분석과 그 생리활성)

  • Kim, Do Hoy;Jung, Yang Sam;Yoon, Michung;Yoon, Yoosik;Shin, Soon Shik
    • Herbal Formula Science
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    • v.24 no.4
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    • pp.353-365
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    • 2016
  • Objectives : We analysed Gyejibongnyeong-hwan's compatibility principle and investigated biological activities by categorizing with molecular level, cellular level, animal level and human level based on Korean study for this formula. Methods : Gyejibongnyeong-hwan's compatibiltity principle was examined by the system of chief, deputy, assistant, and envoy. We looked into studies that presented in Korea from 1956 to 2016 about Gyejibongnyeong-hwan through Korea Institute of Oriental Medicine, Korean medicine information system (OASIS). Then classify into molecular level, cellular level, animal level and human level to analyse. Results : According to the system of chief, deputy, assistant, and envoy, chief herb is Cinnamomi Ramulus, deputy herb is Persicae Semen, assistant herb is Moutan Cortex, Paeoniae Radix, Poria, and envoy herb is Mel. Biological activities can be detected in transcription factors, enzymes, and inflammatory mediators for molecular level. For cellular level, it can be determined in human uterine endometrial cancer cell, human hepatocarcinoma cell, and human platelets. In mouse and rats for animal level, in overian cystoma, menorrhalgia, quality of life improvement in postmenopausal women, and blood stasis with motor vehicle accident for human level, biological activities was caught. Conclusions : From above results, Gyejibongnyeong-hwan is composed in line with the system of chief, deputy, assistan, and envoy. Biological activities are effective to improvement of menorrhalgia, anti-cancer, anti-oxidative, anti-inflammation, improvement of atherosclerosis, analgesic, anti-convulsion, wound healing, and improvement of liver function.