| dc.identifier.uri | http://hdl.handle.net/11401/78275 | |
| dc.description.sponsorship | This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. | en_US |
| dc.format | Monograph | |
| dc.format.medium | Electronic Resource | en_US |
| dc.language.iso | en_US | |
| dc.type | Dissertation | |
| dcterms.abstract | Ordered membrane domains rich in sphingolipids and sterols (lipid rafts) are thought to be important in many biological processes. However, it is difficult to distinguish domain-dependent biological functions from ones having a specific sterol dependence. Sterol substitution has the potential to help distinguish these cases. This study uses sterol substitution to probe effects of sterol properties upon two cellular functions; endocytosis and bacterial uptake into mammalian cells. Lipid rafts have been hypothesized to participate in endocytosis based on inhibition of endocytosis by removal of cholesterol. To investigate the role of the sterol in endocytosis, we replaced cholesterol in MDA-MB-231 cells with a diverse set of sterols. Both clathrin-mediated endocytosis of transferrin and clathrin-independent endocytosis of clustered placental alkaline phosphatase were measured. The ability of a sterol to support lipid raft formation was necessary for endocytosis. However, it was not sufficient, because a sterol with with a 3α-OH group did not support endocytosis although it can support ordered domain formation. Double bonds in sterol rings and an aliphatic tail structure identical to that of cholesterol were neither necessary nor sufficient to support endocytosis. Substitution was also used to study the effect of sterol properties upon pathogen uptake. Yersinia pseudotuberculosis was used as the pathogen and cholesterol in host mammalian cells was substituted with various sterols. Y. pseudotuberculosis attachment to host cells was independent of sterol structure, but only cholesterol, desmosterol and 7-dehydrocholesterol supported its internalization into host cells. Because the Y. pseudotuberculosis adhesins invasin and YadA interact with, and cluster, host cell β1 integrin in a fashion mediating bacterial internalization, the sterol dependence of wild type strain internalization was compared to that of adhesin mutant Δinv, ΔyadA, and ΔinvΔyad bacteria and that of β1 integrin. In single mutants the dependence of internalization upon sterol structure was similar to wild type. The ΔinvΔyadA double mutant could not support significant internalization because it did not support bacterial attachment to host cells. The sterol dependence of Y. pseudotuberculosis internalization did not match that for endocytosis of antibody-clustered β1 integrin, which showed a sterol dependence similar to that for transferrin and placental alkaline phosphatase. The narrower sterol dependence of Y. pseudotuberculosis than endocytosis of membrane proteins makes a possibility to develop an agent to interfere with bacterial uptake without inhibiting the cellular endocytosis. | |
| dcterms.available | 2018-06-21T13:38:50Z | |
| dcterms.contributor | Brown, Deborah A | en_US |
| dcterms.contributor | London, Erwin | en_US |
| dcterms.contributor | Thanassi, David | en_US |
| dcterms.contributor | Del Poeta, Maurizio | en_US |
| dcterms.creator | Kim, Ji Hyun | |
| dcterms.dateAccepted | 2018-06-21T13:38:50Z | |
| dcterms.dateSubmitted | 2018-06-21T13:38:50Z | |
| dcterms.description | Department of Molecular and Cellular Biology | en_US |
| dcterms.extent | 133 pg. | en_US |
| dcterms.format | Application/PDF | en_US |
| dcterms.format | Monograph | |
| dcterms.identifier | http://hdl.handle.net/11401/78275 | |
| dcterms.issued | 2017-12-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Made available in DSpace on 2018-06-21T13:38:50Z (GMT). No. of bitstreams: 1
Kim_grad.sunysb_0771E_13523.pdf: 4578924 bytes, checksum: 5e08b7cd50cb546def70b408aeade486 (MD5)
Previous issue date: 12 | en |
| dcterms.subject | Cytology | |
| dcterms.subject | bacteria uptake | |
| dcterms.subject | Biochemistry | |
| dcterms.subject | cholesterol | |
| dcterms.subject | cyclodextrin | |
| dcterms.subject | endocytosis | |
| dcterms.subject | lipid raft | |
| dcterms.subject | membrane | |
| dcterms.title | Effects of sterols upon clathrin-mediated or -independent endocytosis and uptake of Yersinia pseudotuberculosis | |
| dcterms.type | Dissertation | |
