• Epac: new emerging cAMP-binding protein

    Schematic representation of domain structure and genomic organization of Epac protein isoforms. Epac1 and Epac2 consist of the N-terminal regulatory region and the C-terminal catalytic region in common, which are composed of functional multi-domains. The regulatory region contains a cyclic nucleotide-binding (CNB) domain and a dishevelled, Egl-10, Pleckstrin (DEP) domain. The CNB domain of Epac1 and CNB-B domain of Epac2 bind cAMP with a high affinity leading to Epac protein activation. The extra CNB-A domain of Epac2A1 and Epac2A2 bind cAMP with a relatively low affinity compared with the conserved CNB-B domain and is not involved in activation of Epac2. The Dishevelled, Egl-10, Pleckstrin (DEP) domain has a role in the subcellular localization of Epac protein. In the catalytic region, a RAS exchange motif (REM) domain interacting with the guanine nucleotide exchange factor (GEF) region stabilizes a GEF for Ras-like small GTPases (RasGEF) domain which is responsible for biological function of Epac protein. The RAS-association (RA) domain regulates perinuclear localization of Epac1 and plasma membrane localization of Epac2.
  • Diffusion-based determination of protein homodimerization on reconstituted membrane surfaces

    (A) In fluorescence correlation spectroscopy, a confocal laser illumination spot is used to monitor the intensity fluctuation due to fluorescence molecules diffusing in and out of the focus. The auto-correlation function (ACF) of the resulting time trace is used to compute the particle number (N, from the y-intercept) and residence time (τd, from the half-point of the ACF decay) of the fluorescent molecule in the laser focus, which is related to the diffusion coefficient by w2 = 4Dτd. In this example, a GFP-labeled protein on a supported lipid bilayer is excited by a blue (488 nm) laser. (B) In total internal relfection fluorescence microscopy (TIRFM) single molecule tracking, the displacement of the particle between each frame are reconstructed into particle trajectories (example trajectory shown in inset). The step size distribution may be used to calculate the diffusion coefficient and the relative population of multiple diffusing species, following the step size equation P(r) (Equations 5 and 6 for single and two species, respectively). The fit to a single species step size distribution is shown. (C) Left: theoretical binding curves for a dimerization reaction for a wide range of dissociation constants, right: simulated FCS data using experimentally determined diffusion coefficients for monomers and dimers for the same dissociation constants.

BMB Reports 2021; 54(4): 189~232
Invited Mini Review
Regulation of polyubiquitin genes to meet cellular ubiquitin requirement
Seung-Woo Han, Byung-Kwon Jung & Kwon-Yul Ryu
BMB Reports 2021; 54(4): 189-195  https://doi.org/10.5483/BMBRep.2021.54.4.005
Contributed Mini Review
The blood cerebrospinal fluid barrier orchestrates immunosurveillance, immunoprotection, and immunopathology in the central nervous system
Maria Ayub, Hee Kyung Jin & Jae-sung Bae
BMB Reports 2021; 54(4): 196-202  https://doi.org/10.5483/BMBRep.2021.54.4.205
Lysophosphatidylcholine aggravates contact hypersensitivity by promoting neutrophil infiltration and IL17 expression
Mi Hye Song, Anupriya Gupta, Hye One Kim & Kwonik Oh
BMB Reports 2021; 54(4): 203-208  https://doi.org/10.5483/BMBRep.2021.54.4.193
CD1d deficiency limits tolerogenic properties of peritoneal macrophages
Fathihah Basri, Sundo Jung , Se Hoon Park & Se-Ho Park
BMB Reports 2021; 54(4): 209-214  https://doi.org/10.5483/BMBRep.2021.54.4.183
Lin28a ameliorates glucotoxicity-induced β-cell dysfunction and apoptosis
Yeo Jin Hwang, Gwon-Soo Jung, WonBae Jeon & Kyeong-Min Lee
BMB Reports 2021; 54(4): 215-220  https://doi.org/10.5483/BMBRep.2021.54.4.255
Gluconeogenic signals regulate hepcidin gene expression via a CRBN-KLF15 axis
Jeong-Rang Jo, Sung-Eun Lee, Seungwon An, Balachandar Nedumaran, Swati Ghosh, Keun-Gyu Park & Yong Deuk Kim
BMB Reports 2021; 54(4): 221-226  https://doi.org/10.5483/BMBRep.2021.54.4.215
Mitochondrial dysfunction induced by callyspongiolide promotes autophagy-dependent cell death
Soohyun Lee , Yoonjeong Jeong , Jae-Seok Roe, Hoyoung Huh, Sang Hoon Paik & Jaewhan Song
BMB Reports 2021; 54(4): 227-232  https://doi.org/10.5483/BMBRep.2021.54.4.037


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April 2021
Volume 54
Issue 4

2019 SCI Impact Factor 3.167


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