• The Journal of Natural Sciences
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• v.8 no.2
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• pp.35-41
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• 1996

To find the substrate interacting site of the MCAT1, charged amino acid residues in the transmembrane domain were changed to opposite charged amino acids and studied the arginine uptake, gp70 binding, efflux and protein expression using the Xenopus oocyte expression method. Among the five mutants of MCAT1, the D403K showed the most interesting characteristics, which had normal gp70 binding but low arginine uptake function, that means the normal expression on the membrane but decreased transport function. All mutants except K211E showed decreased arginine efflux, and kinetic study showed decreased Vmax. Together, Clu(403) residue of MCAT1 may show the possible substrate interacting site in the transmembrane domain of MCAT1.

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.219.1-219.1
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• 2000

• BMB Reports
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• v.47 no.12
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• pp.655-659
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• 2014

Integrin-mediated cell adhesion is important for development, immune responses, hemostasis and wound healing. Integrins also function as signal transducing receptors that can control intracellular pathways that regulate cell survival, proliferation, and cell fate. Conversely, cells can modulate the affinity of integrins for their ligands a process operationally defined as integrin activation. Analysis of activation of integrins has now provided a detailed molecular understanding of this unique form of "inside-out" signal transduction and revealed new paradigms of how transmembrane domains (TMD) can transmit long range allosteric changes in transmembrane proteins. Here, we will review how talin and mediates integrin activation and how the integrin TMD can transmit these inside out signals.

• Journal of fish pathology
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• v.19 no.3
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• pp.227-233
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• 2006

Olive flounder immunoreceptor DAP10 homologue cDNA was cloned from a peripheral blood lymphocytes (PBLs) cDNA library. The length of the olive flounder DAP10 cDNA is 473bp and it contains an open reading frame of 234bp. The predicted polypeptide sequence is 78 amino acids, consisting of a 22-amino acid leader, an 11-amino acid extracellular domain, a 21-amino acid transmembrane segment, and a 24-amino acid cytoplasmic domain. The amino acid sequence of olive flounder DAP10 has 56%, 50%, 32%, 31%, and 31% sequence identity with zebrafish DAP10, catfish DAP10, cattle DAP10, rat DAP10 and Monkey DAP10, respectively. Olive flounder DAP10 has a conserved aspartic acid in the transmembrane domain and a phophatidylinositol-3 kinase-binding site (YxxM/V) in the cytoplasmic region. Genomic organization reveals that olive flounder DAP10 comprises five exons and four introns. A phylogenetic analysis based on the deduced amino acid sequence grouped the olive flounder DAP10 with other species DAP10. In RT-PCR analysis, DAP10 transcripts were detected predominantly in PBLs, kidney, spleen and intestine.

• BMB Reports
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• v.47 no.10
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• pp.563-568
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• 2014

Human genome projects have enabled whole genome mapping and improved our understanding of the genes in humans. However, many unknown genes remain to be functionally characterized. In this study, we characterized human chromosome 4 open reading frame 34 gene (hC4orf34). hC4orf34 was highly conserved from invertebrate to mammalian cells and ubiquitously expressed in the organs of mice, including the heart and brain. Interestingly, hC4orf34 is a novel ER-resident, type I transmembrane protein. Mutant analysis showed that the transmembrane domain (TMD) of hC4orf34 was involved in ER retention. Overall, our results indicate that hC4orf34 is an ER-resident type I transmembrane protein, and might play a role in ER functions including $Ca^{2+}$ homeostasis and ER stress.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.485-492
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• 2006

The PrrBA two-component system is one of the major regulatory systems that control expression of photosynthesis genes in response to changes in oxygen tension in the anoxygenic photosynthetic bacterium, Rhodobacter sphaeroides. The system consists of the PrrB histidine kinase and the PrrA response regulator. The N-terminal transmembrane domain of PrrB serves as a signal-sensing domain and comprises six transmembrane helices forming three periplasmic loops and two cytoplasmic loops. The $3^{rd}$ and $4^{th}$ transmembrane helices and the $2^{nd}$ periplasmic loop were suggested to play a crucial role in redox-sensory function. In this study we demonstrated that mutations of Asp-90, Gln-93, Leu-94, Leu-98, and Asn-106 in the $2^{nd}$ periplasmic loop and its neighboring region led to severe defects in PrrB sensory function, indicating that these amino acids might be related to the redox-sensing function of PrrB. The mutant forms (D90E, D90N, and D90A) of PrrB were heterologously overexpressed in Escherichia coli, purified by means of affinity chromatography and their autokinase activities were comparatively assessed. The D90N form of PrrB was shown to possess higher autokinase activity than the wild-type form of PrrB, whereas the D90E form of PrrB displayed lower autokinase activity than the wild-type form of PrrB. The D90A mutation led to the loss of PrrB autokinase activity.

• BMB Reports
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• v.32 no.4
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• pp.405-408
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• 1999

The transactivation potential of HIV-1 Vpu was identified from the yeast two-hybrid screening process. The helix II domain of HIV-1 Vpu protein and mutant Vpu protein lacking the transmembrane domain exhibited transactivation of the LacZ and Leu2 reporter genes carrying LexA upstream activating sequences, but full-length HIV-1 Vpu and the helix I domain of HIV-1 Vpu did not. The helix II domain of HIV-1 Vpu consists of a number of acidic amino acids, and is especially rich in glutamic acid, a characteristic of many transcription factors. This result suggests that protein-protein interaction may occur through the acidic helix II domain of HIV-1 Vpu.

• Molecules and Cells
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• v.40 no.12
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• pp.954-965
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• 2017

Mammalian genomes are well established, and highly conserved regions within odorant receptors that are unique from other G-protein coupled receptors have been identified. Numerous functional studies have focused on specific conserved amino acids motifs; however, not all conserved motifs have been sufficiently characterized. Here, we identified a highly conserved 18 amino acid sequence motif within transmembrane domain seven (CAS-TM7) which was identified by aligning odorant receptor sequences. Next, we investigated the expression pattern and distribution of this conserved amino acid motif among a broad range of odorant receptors. To examine the localization of odorant receptor proteins, we used a sequence-specific peptide antibody against CAS-TM7 which is specific to odorant receptors across species. The specificity of this peptide antibody in recognizing odorant receptors has been confirmed in a heterologous in vitro system and a rat-based in vivo system. The CAS-TM7 odorant receptors localized with distinct patterns at each region of the olfactory epithelium; septum, endoturbinate and ectoturbinate. To our great interests, we found that the CAS-TM7 odorant receptors are primarily localized to the dorsal region of the olfactory bulb, coinciding with olfactory epithelium-based patterns. Also, these odorant receptors were ectopically expressed in the various non-olfactory tissues in an evolutionary constrained manner between human and rats. This study has characterized the expression patterns of odorant receptors containing particular amino acid motif in transmembrane domain 7, and which led to an intriguing possibility that the conserved motif of odorant receptors can play critical roles in other physiological functions as well as olfaction.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.548-548
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• 2003

• Proceedings of the Microbiological Society of Korea Conference
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• 1999.04a
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• pp.48.1-48.1
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• 1999