Four small ubiquitin-like modifier (SUMO) isoforms termed SUMO-1, -2, -3 and -4 have been identified in human. Most SUMO-1/2 proteins are localized in nucleus, whereas SUMO-1 protein exhibits 44% homolog with SUMO-2 protein. Over 50 proteins have been identified as the target proteins for SUMO-1 modification and these include transcription factors, their cofactors, regulators, nuclear body proteins, nuclear pore complex proteins, DNA repair proteins, and viral proteins. However, only a handful of SUMO-2 targets are known and SUMO-2 modification may response to environmental stress. SUMO-1 may interact with Fas/APO-1 and TNF receptor 1 on yeast two hybrid interactions; however, it is not clear whether SUMO would enhance apoptosis or response to biological stress. Helicobacter pylori (H. pylori) defined as a gastric carcinogen is definite a biological stress to the cells. It causes gastric epithelial cell damage by apoptosis. In this study whether the SUMO-1/2 pathway constitutes an element of the cellular response to the H. pylori infection was examined. Overexpression of SUMO-1/2 for 12 hours had no effects on the apoptotic activities of cells; however it enhanced apoptosis during H. pylori infection. Overexpression of SUMO-1/2 for 48 hours increased the apoptosis of cells; however only SUMO-2 enhanced apoptosis significantly during H. pylori infection. The enhancements are more powerful for SUMO-2 than that of SUMO-1. Inactive SUMO, a cytoplasm dispersed sumoylation-incompetent mutant, eliminates such activities, suggesting that sumoylation or SUMO interactions are involved in the apoptotic enhancement. The percentages of cells with cytoplasmic SUMO-2 were increased 22% by H. pylori infection for 2 hours and SUMO-1 were increased 11%. The translocalization of SUMO-1 was blocked by leptomycin B; however, it did not work on SUMO-2. Leptomycin B could also inhibit SUMO-1 enhanced apoptosis during H. pylori infection, whereas it had no effects on SUMO-2. It is concluded that SUMO-1/2 pathway constitutes an element of the cellular response to H. pylori infection by enhancing apoptosis through shuttling from nucleus to cytoplasm. SUMO-1 is via a CRM1-dependent pathway while SUMO-2 is via a CRM1-independent pathway.

Thesis (M.S.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 119-147).

Thesis (M.S.)--University of Toledo, 2009. / Typescript. "Submitted as partial fulfillment of the requirements for The Master of Science degree in Chemistry." "A thesis entitled"--at head of title. Bibliography: leaves 100-104.

Thesis (M.S.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 119-147).

Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xxv, 330 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Kathryn A. Eaton, Dept. of Veterinary Bioscience. Includes bibliographical references (p. 297-330).

Thesis (Ph. D.)--University of Queensland, 2002. / Includes bibliographical references.

No description available.

There were three main aims to this thesis: 1. to test whether infection with Helicobacter pylori was related specifically to chronic atrophic gastritis (CAG), a precursor of gastric cancer; and to measure the specificity and sensitivity of Helicobacter pylori antibody markers for detecting H.pylori infection of the gastric mucosa; and CAG; 2. to measure the distribution of H.pylori in relation to sociodemographic, dietary and lifestyle characteristics in non-clinical populations from Caerphilly (Wales), Italy, China, and Kenya; 3. to examine the relationship between H.pylori and gastric cancer. H.pylori was strongly associated with CAG and H.pylori antibody level was a sensitive and specific marker of both infection (84.8%, 92.7%) and CAG (71.4%, 90.9%). In Caerphilly and Italy, the prevalence of H.pylori increased steeply to 40-50% in those aged 45-54 years and levelled off in older age groups. In China, over 50% of those aged 35-44 were infected. In Kenya, almost all people studied between 18-30 years were infected with H.pylori. In Caerphilly, H.pylori infection was significantly higher in poorer socioeconomic groups, whilst in Italy, socioeconomic differences with regard to infection were in the same direction but not as pronounced. In Caerphilly, H.pylori infection was related to the number of the subject's siblings but not to the number of children or adults sharing the house of the subject. In Caerphilly, those infected with H.pylori consumed less vitamin C and more alcohol than those not infected. Those infected in Italy consumed more vitamin C but similar amounts of alcohol than those not infected. In China, smoking was inversely related to H.pylori infection. In China, a geographic correlation of +0.34 (2p = 0.02) was found between the prevalence of H.pylori infection (measured in 46 counties) and gastric cancer mortality. There was also a positive (but not significant) correlation with peptic ulcer mortality. No other type of cancer showed a significant association with H.pylori.

The perinuclear theca (PT) is a cytoskeletal structure that covers the nucleus of mammalian spermatozoa and is believed to have a membrane binding role. The objectives of this study were to analyze the protein composition of the mouse PT, to identify its major protein component, and to characterize this protein's transcriptional and translational origins during spermatogenesis. The PT was extracted from demembranated and acrosome-depleted mouse sperm heads by alkaline treatment. The protein profile of the PT extract was composed of several polypeptides of which a 15 kDa subacrosomal protein predominated and was found to be immunocross-reactive with a previously cloned 15 kDa PT protein of the rat (PERF 15) that belongs to a family of lipid binding proteins. A primer pair designed from rat PERF 15 cDNA was then used to screen a mouse testicular cDNA library by polymerase chain reaction (PCR). The deduced amino acid sequence obtained from the PCR product was almost identical to the testicular-specific rat PERF 15. Developmental Northern blots and in situ hybridization studies performed with riboprobes encoding the mouse PERF 15 cDNA revealed that mRNA levels were highest in round and early elongating mouse spermatids. Immunohistochemistry indicated that PERF 15 began to be expressed in the cytoplasm of mid-pachytene spermatocytes and appeared to reach maximum expression in the distal cytoplasm of late elongating mouse spermatids, long after transcriptional arrest. During the development of round and early elongating spermatids, the immunolabel became progressively concentrated over the anterior half of the spermatid nucleus suggesting a subacrosomal deposition of PERF 15 during this phase of mouse spermatogenesis.

Proefschrift Universiteit van Amsterdam. / Met lit. opg.