Nanodiscs Stabilize Anabaena Sensory Rhodopsin for Transcriptional Regulation Studies

College of Natural Resources & Sciences

Anabaena Sensory Rhodopsin (ASR) is a retinal containing membrane protein from Anabaena nostoc. ASR undergoes an orange-light induced conformational change from an all trans form to a 13-cis form, which is associated with the release of a bound transducer protein ASRT. It is proposed that the ASR/ASRT complex directly controls the transcription of phycocyanin (cpc-gene) and phycoerythrocyanin (pec-gene). In order to study this protein complex, ASR nanolipoprotein particles (nanodiscs) were assembled, which allows both ends of the ASR protein to be studied. These particles will enable, the main goal of this research, which is to identify the mechanism of the ASR/ASRT control of transcription.

Nanodiscs Stabilize Anabaena Sensory Rhodopsin for Transcriptional Regulation Studies

College of Natural Resources & Sciences

Anabaena Sensory Rhodopsin (ASR) is a retinal containing photoactive membrane protein from the cyanobacterium Anabaena. ASR is part of a protein complex which has been proposed, but never demonstrated, to control the transcription of the cpc-genes involved in chromatic adaption. We isolated and characterized ASR from engineered E. coli for construction of protein lipid nanodiscs. Our ASR nanodiscs were soluble and allow for protein access from the top and bottom of the bilayer. Our next steps will involve examination of the lipid environment and to investigate DNA binding. Results of these studies may allow for future use of these proteins as photo-active transcriptional regulators.

Nanodiscs stabilize Anabaena sensory rhodopsin trimers for regulatory binding studies

College of Natural Resources & Sciences

Anabaena Sensory Rhodopsin (ASR), a photoactive membrane protein, undergoes light induced conformational change associated with release of a transducer protein, ASRT. This complex is proposed to control transcription. However, DNA binding to ASR has not been demonstrated. We prepared ASR in soluble nanodiscs. Our data show ASR nanodiscs had a retinal absorbance shift (≈548 - 537 nm). DLS of ASR nanodiscs, separated by SEC, displayed two populations (21.9 ± 6.3 and 31.1 ± 12.5 nm). These populations may represent varying oligomeric states. Preliminary data from crosslinking studies suggest ASR exist in a trimeric state. We conclude ASR is stabilized in the nanodiscs, enabling studies of ASR.

Nanoscale Modifications to the RsaA S-Layer Protein Enhance Lead Binding in Caulobacter Vibriodes

College of Natural Resources & Sciences

Heavy metal contamination of soils and waterways due to industrial processes continues to be a problem in the United States. Recent reports indicate that microbial surface layers (S-layers) can bind and sequester heavy metals, thereby removing them from the environment. Our approach is to enhance this process for lead bioremediation. Through this study, C. vibrioides strains were morphologically characterized through transmission and scanning electron microscopy, and recombinant surface layer export was genetically verified. Using a fluorescence-based assay, we show that our engineered strains were 10% more effective in bioremediating lead than the wildtype in nanomolar concentrations.

Nanoscale Modifications to the RsaA S-Layer Protein Enhance Lead Binding in Whole Cells

College of Natural Resources & Sciences

Due to the many industrial processes of modern America, heavy metal contamination of our waterways, specifically in densely populated areas, has become a major issue. The Prokaryotic species Caulobacter vibrioides exhibits a surface layer protein, RsaA, forming a 2-D crystallin array above the cell membrane. RsaA can be modified to exhibit a high binding potential with many of the charged ions, such as heavy metals, which are found in waterways. Here we show through an quantitative fluorescence assay that upon exposure to 39.063nM Pb solution, engineered C. vibrioides strains Hcm 027, and 028 remediated approximately 10% more Pb than the wildtype, Hcm 009.

Nanoscale Modifications to the RsaA S-Layer Protein Enhance Lead binding in Whole Cells

College of Natural Resources & Sciences

Heavy metal contamination of soils and waterways due to industrial processes, continues to be a problem in the United States. Recent reports indicate that microbial surface layers (S-layers) are able to bind and sequester heavy metals, thereby removing them from the environment. Our approach is to enhance this process for heavy metal bioremediation. Using a highly sensitive fluorescent dye, lead remediation was measured in the nanomolar range. Results show that upon exposure to 39.0 nM Pb solution engineered C. vibrioides strains Hcm 027,028, remediated the solution to, 9.6 ± 0.3 nM, 9.0 ± 0.2 nM respectively and 13.3 ± 0.1 nM for the wild type.

Native Alaskans and Wildlife Interactions and Issues

College of Natural Resources & Sciences

This project encompasses the relationship and issues connected to Alaskan Natives and wildlife. Their relationship to the land and wildlife is deeply rooted in their history, and most Alaska natives practice traditional hunting and gathering practices. Native Alaskan interactions with the natural world is interwoven in the way in which they define subsistence, which is synonymous with culture, identity, and self-determination and involves conservation and perpetuation of natural resources. The US Federal and Alaska State government define subsistence differently and have passed Acts and policies that interfere with the Native’s aboriginal hunting and fishing rights.

Native American Storytelling

College of Natural Resources & Sciences

We are focusing our topic on the role that animals have in Native American storytelling, and how these animal's behaviors in real life are reflected in the stories. Storytelling is a way of communication that Natives use to share knowledge between generations; often, these stories use animals as symbolism. Our group is composed of all zoology majors interested in studying animal behavior, and we will compare the personality traits and characteristics of these animals to their role played in these stories.

Natural History and Basking Habits of Western Pond Turtles

College of Natural Resources & Sciences

This research represents the preliminary results of a longer term project in Sequoia National Park, California. I used temperature dataloggers to investigate western pond turtle behavior to better understand their natural history and thus inform monitoring protocol and conservation. These data suggest that snorkel surveys used to monitor turtle populations may be more effective if conducted at night. In addition, these data indicate the potential for intraspecific niche partitioning among turtles according to age. These early results hint at unique turtle behavior that is otherwise difficult to observe for a cryptic species and thereby warrant further investigation.

NDCI Analysis and Change Detection for Coral Reef Habitats of Duncan Island In South Chinese Sea from 2016 to 2018

College of Natural Resources & Sciences

Mismanagement of coral reef habitats for construction has impacted on rapid destruction of most biodiverse coral reefs of South Chinese sea. This project examines how coral reef habitats changed in Duncan island of South Chinese sea using object based image analysis (OBIA) and coral index. We estimated the coral changes over time with different land-use classes. The unchanged coral acreage was 7.80 acres between 2016-2017, 1.21 acres between 2017-2018 and 8.22 acres between 2016-2018. The coefficient of agreement for the classification is ranged from 0.55 to 0.60. NDCI Analysis of coral regions surrounding Duncan island revealed vegetation change in coral health.