Browsing by Author "Kim, Junghyun"

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    An Amphipathic Alpha-Helix Domain from Poliovirus 2C Protein Tubulate Lipid Vesicles
    Varkey, Jobin; Zhang, Jiantao; Kim, Junghyun; George, Gincy; He, Guijuan; Belov, George A.; Langen, Ralf; Wang, Xiaofeng (MDPI, 2020-12-18)
    Positive-strand RNA viruses universally remodel host intracellular membranes to form membrane-bound viral replication complexes, where viral offspring RNAs are synthesized. In the majority of cases, viral replication proteins are targeted to and play critical roles in the modulation of the designated organelle membranes. Many viral replication proteins do not have transmembrane domains, but contain single or multiple amphipathic alpha-helices. It has been conventionally recognized that these helices serve as an anchor for viral replication protein to be associated with membranes. We report here that a peptide representing the amphipathic α-helix at the N-terminus of the poliovirus 2C protein not only binds to liposomes, but also remodels spherical liposomes into tubules. The membrane remodeling ability of this amphipathic alpha-helix is similar to that recognized in other amphipathic alpha-helices from cellular proteins involved in membrane remodeling, such as BAR domain proteins. Mutations affecting the hydrophobic face of the amphipathic alpha-helix severely compromised membrane remodeling of vesicles with physiologically relevant phospholipid composition. These mutations also affected the ability of poliovirus to form plaques indicative of reduced viral replication, further underscoring the importance of membrane remodeling by the amphipathic alpha-helix in possible relation to the formation of viral replication complexes.
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    Lonely Consumers: When, How, and Why Does Loneliness Influence Consumer Behavior?
    Kim, Junghyun (Virginia Tech, 2017-04-25)
    Although the advance of social media has enabled people to build social connections much more easily than ever before, loneliness—an aversive feeling of being isolated and disconnected—persists in modern society. In this dissertation, I examine when, how, and why loneliness influences consumer behavior. First, I develop an experimental method to induce loneliness and identify a circumstance that experimenters can obtain a successful loneliness priming effect. Across three experiments, I demonstrate that the same loneliness primes produce different loneliness responses based on the availability of cognitive resources. Specifically, participants who are cognitively depleted tend to rely on responses evoked by the loneliness primes (showing the intended loneliness priming effect) while those with abundant cognitive resources are not affected by the loneliness primes. Building on the findings from Experiments 1-3, I investigate how loneliness affects consumer behaviors in two different marketing contexts, nostalgic product consumption and charitable giving by focusing on how consumers cope with loneliness through consumption. In Experiments 4-5, I demonstrate that consumers who lack cognitive resources tend to form positive attitudes toward nostalgic products when experiencing loneliness. In Experiments 6-7, I show that lonely consumers with limited cognitive resources are likely to donate money to a charitable organization. Additionally, I find that consumers can regulate feelings of loneliness by spending money either for themselves (i.e., nostalgic products) or for others (i.e., charitable giving). This dissertation contributes to our understanding of loneliness in marketing by identifying a circumstance in which such emotional distress significantly influences consumer behavior and by showing how consumers spend money to cope with loneliness.