• BMB Reports
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• 제46권2호
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• pp.73-79
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• 2013

Polycystic kidney disease (PKD) is a common hereditary disorder which is characterized by fluid-filled cysts in the kidney. Mutation in either PKD1, encoding polycystin-1 (PC1), or PKD2, encoding polycystin-2 (PC2), are causative genes of PKD. Recent studies indicate that renal cilia, known as mechanosensors, detecting flow stimulation through renal tubules, have a critical function in maintaining homeostasis of renal epithelial cells. Because most proteins related to PKD are localized to renal cilia or have a function in ciliogenesis. PC1/PC2 heterodimer is localized to the cilia, playing a role in calcium channels. Also, disruptions of ciliary proteins, except for PC1 and PC2, could be involved in the induction of polycystic kidney disease. Based on these findings, various PKD mice models were produced to understand the roles of primary cilia defects in renal cyst formation. In this review, we will describe the general role of cilia in renal epithelial cells, and the relationship between ciliary defects and PKD. We also discuss mouse models of PKD related to ciliary defects based on recent studies.

• The Korean Journal of Physiology and Pharmacology
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• 제23권3호
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• pp.219-227
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• 2019

Polycystic kidney disease 2-like-1 (PKD2L1), polycystin-L or transient receptor potential polycystin 3 (TRPP3) is a TRP superfamily member. It is a calcium-permeable non-selective cation channel that regulates intracellular calcium concentration and thereby calcium signaling. Although the calmodulin (CaM) inhibitor, calmidazolium, is an activator of the PKD2L1 channel, the activating mechanism remains unclear. The purpose of this study is to clarify whether CaM takes part in the regulation of the PKD2L1 channel, and if so, how. With patch clamp techniques, we observed the current amplitudes of PKD2L1 significantly reduced when co-expressed with CaM and $CaM{\triangle}N$. This result suggests that the N-lobe of CaM carries a more crucial role in regulating PKD2L1 and guides us into our next question on the different functions of two lobes of CaM. We also identified the predicted CaM binding site, and generated deletion and truncation mutants. The mutants showed significant reduction in currents losing PKD2L1 current-voltage curve, suggesting that the C-terminal region from 590 to 600 is crucial for maintaining the functionality of the PKD2L1 channel. With PKD2L1608Stop mutant showing increased current amplitudes, we further examined the functional importance of EF-hand domain. Along with co-expression of CaM, ${\triangle}EF$-hand mutant also showed significant changes in current amplitudes and potentiation time. Our findings suggest that there is a constitutive inhibition of EF-hand and binding of CaM C-lobe on the channel in low calcium concentration. At higher calcium concentration, calcium ions occupy the N-lobe as well as the EF-hand domain, allowing the two to compete to bind to the channel.

• 한국응용곤충학회지
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• 제50권2호
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• pp.131-139
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• 2011

본 연구는 음파 처리에 따른 아메리카잎굴파리(Liriomyza trifolii)의 생리 변화를 발육 시기별로 분석하였다. 유충의 섭식량은 섭식을 통해 형성된 잎 내부 갱도의 길이로 분석했다. 이때 5,000 Hz (95 dB)의 음파 처리는 섭식 행동을 크게 둔화시켰다. 이러한 스트레스 음파는 또한 용발육에 영향을 주어 315 - 5,000 Hz 음파 범위에서 발육 지연 효과를 나타냈고, 1,000 - 5,000 Hz 음파 범위에서 우화를 억제하였다. 스트레스 음파는 암컷의 산란 행동을 억제시켰으나 성충의 주광성 행동에는 영향을 주지 않았다. 스트레스 음파(5,000 Hz, 95 dB)를 받은 용은 이차원 전기영동 분석 결과 단백질 발현 양상에서 무처리구와 뚜렷한 차이를 보였다. 특정 단백질에 대한 MALDI-TOF 분석 결과는 trafficking protein particle complex I, triosephosphate isomerase, hypothetical protein TcasGA2_TC013388, polycystin-2, paraneoplastic neuronal antigen MA1 및 tropomyosin I (isoform M)의 단백질들이 무처리구에서 발견되고, 음파 처리구에서는 소멸되었다. 반면에 DOCK9, cytoskeletal keratin II 및 $F_0F_1$-ATP synthase beta subunit은 스트레스 음파 처리에 따라 새롭게 나타나는 단백질로 판명되었다. 이러한 스트레스 음파는 아메리카잎굴파리의 살충제에 대한 감수성을 크게 증가시켰다. 이상의 결과는 아메리카잎굴파리의 생리 과정을 교란하는 스트레스 음파가 작용한다는 것을 제시하고 있다. 또한 본 연구는 이러한 스트레스 음파를 이용하여 아메리카잎굴파리에 대한 새로운 물리적 해충 방제 기술 개발 가능성을 제시하고 있다.

• BMB Reports
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• 제37권5호
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• pp.612-617
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• 2004

Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disorder characterized by the formation of fluid-filled cysts in the kidney and progressive renal failure. Other manifestations of ADPKD include the formation of cysts in other organs (liver, pancreas, and spleen), hypertension, cardiac defects, and cerebral aneurysms. The loss of function of the polycystin -1 and -2 results in the formation of epithelium-lined cysts, a process that depends on initial epithelial proliferation. cDNA microarrays powerfully monitor gene expression and have led to the discoveries of pathways regulating complex biological processes. We undertook to profile the gene expression patterns of epithelial cells derived from the cysts of ADPKD patients using the cDNA microarray technique. Candidate genes that were differently expressed in cyst tissues were identified. 19 genes were up-regulated, and 6 down-regulated. Semi-quantitative RT-PCR results were consistent with the microarray findings. To distinguish between normal and epithelial cells, we used the hierarchical method. The results obtained may provide a molecular basis for understanding the biological meaning of cytogenesis.

• The Korean Journal of Physiology and Pharmacology
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• 제24권3호
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• pp.277-286
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• 2020

Polycystic kidney disease 2-like-1 (PKD2L1), also known as polycystin-L or TRPP3, is a non-selective cation channel that regulates intracellular calcium concentration. Calmodulin (CaM) is a calcium binding protein, consisting of N-lobe and C-lobe with two calcium binding EF-hands in each lobe. In previous study, we confirmed that CaM is associated with desensitization of PKD2L1 and that CaM N-lobe and PKD2L1 EF-hand specifically are involved. However, the CaM-binding domain (CaMBD) and its inhibitory mechanism of PKD2L1 have not been identified. In order to identify CaM-binding anchor residue of PKD2L1, single mutants of putative CaMBD and EF-hand deletion mutants were generated. The current changes of the mutants were recorded with whole-cell patch clamp. The calmidazolium (CMZ), a calmodulin inhibitor, was used under different concentrations of intracellular. Among the mutants that showed similar or higher basal currents with that of the PKD2L1 wild type, L593A showed little change in current induced by CMZ. Co-expression of L593A with CaM attenuated the inhibitory effect of PKD2L1 by CaM. In the previous study it was inferred that CaM C-lobe inhibits channels by binding to PKD2L1 at 16 nM calcium concentration and CaM N-lobe at 100 nM. Based on the results at 16 nM calcium concentration condition, this study suggests that CaM C-lobe binds to Leu-593, which can be a CaM C-lobe anchor residue, to regulate channel activity. Taken together, our results provide a model for the regulation of PKD2L1 channel activity by CaM.