Accelerator Design And Hardware Implementation For Distributed Coherent Mesh Beamformer

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Description
This dissertation summarizes achievements and ongoing designs of Field-Programmable Gate Array (FPGA) accelerators for Distributed Coherent Mesh Beamforming (DCMB). The goal of the distributed coherent network beamforming program is to create a network of distributed beams. The radios that make

This dissertation summarizes achievements and ongoing designs of Field-Programmable Gate Array (FPGA) accelerators for Distributed Coherent Mesh Beamforming (DCMB). The goal of the distributed coherent network beamforming program is to create a network of distributed beams. The radios that make up this network must be small in size, weight, power, and cost while being able to overcome long transmission distances and interference. Due to the limitations, a solid communication link can be developed, using high speed to significantly increase signal strength and reduce interference. Two slots were developed to calculate the beamformer for the target platforms. One route is purely FPGA-based. Another option is a hybrid approach that uses the FPGA to do some of the initial calculations and the rest on the Central Processing Unit (CPU). Overall latency was significantly reduced when performing FPGA calculations. DCMB has become a technology for improving wireless communication systems, providing adaptability and efficiency in dynamic environments. This dissertation presents an in-depth study of DCMB with specific innovations in accelerator design and overall controller architecture. I investigate the design and implementation of dedicated accelerators adapted for DCMB tasks, including Finite Impulse Response (FIR) filtering, matrix multiplication, QR decomposition, and compensation on FPGA platforms. These accelerators are specially optimized for real-time processing and better performance on DCMB systems. Compared to soft-core processors, my research shows that hardware accelerators provide significantly faster processing speeds, enabling fast execution and reduced latency in communication systems. In addition, I discuss the design and integration of a general controller that optimizes the operation of accelerators and coordinates the beamforming process between distributed nodes. Through experiments with analytical and simulation tools, my study highlights the superiority of hardware accelerators over soft-core processors for high-speed calculation tasks in DCMB systems.
Date Created
2024
Agent

Partial Purification of Telomerase Enzyme From the Choanoflagellate M. brevicollis

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Description

The transition from circular to linear chromosomes in eukaryotes introduced the “end-replication problem” which is the inherent inability of cellular DNA polymerases to completely replicate linear chromosomal ends. Over evolutionary time, eukaryotes evolved “caps” at their chromosomal ends which are

The transition from circular to linear chromosomes in eukaryotes introduced the “end-replication problem” which is the inherent inability of cellular DNA polymerases to completely replicate linear chromosomal ends. Over evolutionary time, eukaryotes evolved “caps” at their chromosomal ends which are DNA protein complexes known as telomeres. Although telomeric DNA does suffer from the incomplete end-replication, the telomerase ribonucleoprotein enzyme was evolved as the dominant and winning solution to this problem in eukaryotes. The protein component of telomerase known as Telomerase reverse transcriptase (TERT), is well conserved across broad eukaryotic groups. In contrast, the RNA component of telomerase, telomerase RNA (TR) is extremely divergent in terms of sequence and length. This presents insurmountable challenges in the identification of novel TR molecules, especially from more distant and previously unexplored eukaryotic groups. Although animal TRs have been identified and studied in detail, the early evolution and origins of animal telomerases remain a mystery. Thus, it is crucial to study telomerases from the earliest ancestors of animals. The Choanoflagellates are a group of free-living unicellular eukaryotes that are deemed to be the closes living relatives of animals. The choanoflagellate M. brevicollis (Mbr) is a model eukaryote used to study the origins of multicellularity. Thus, we determined to purify M. brevicollis telomerase to isolate, sequence and identify the co-purifying TR. Towards achieving this ultimate goal, this study focuses on partially purifying M. brevicollis telomerase via polyethylene glycol (PEG) precipitation. As the first step, reliable and reproducible culture conditions for M. brevicollis were established. Following this, larger scale cell cultures were grown and used for PEG precipitation. Final concentrations of 5%, 10%, and 20% PEG were used. PEG precipitates were resuspended in buffer and quantitated using Bradford assay. PEG precipitated macromolecular complexes were subject to Western blot using custom generated anti-MbrTERT antibodies which revealed a clear band proximal in size to the 75 kDa marker consistent with the 87 kDa putative MbrTERT. This study serves as a launchpad for the identification of MbrTR towards delineating the early evolution of telomerase in animals.

Date Created
2022-05
Agent

Expression and Purification of the Telomerase RNA Binding Domain of Telomerase Reverse Transcriptase from Purple Sea Urchin (Strongylocentrotus purpuratus)

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Description
Telomerase is a reverse transcriptase that is responsible for the addition of telomeric repeats on to the ends of eukaryotic chromosomes. The purple sea urchin, Strongylocentrotus purpuratus, telomerase enzyme is unique in that its telomerase RNA does not contain the

Telomerase is a reverse transcriptase that is responsible for the addition of telomeric repeats on to the ends of eukaryotic chromosomes. The purple sea urchin, Strongylocentrotus purpuratus, telomerase enzyme is unique in that its telomerase RNA does not contain the ancestrally conserved CR4/5 domain and instead contains the functionally equivalent eCR4/5 domain. Binding between the purple sea urchin TRBD and eCR4/5 domain is currently poorly understood due to eCR4/5's unique structure. In this work the telomerase RNA binding domain, TRBD, of the purple sea urchin telomerase reverse transcriptase, TERT, was fused to maltose binding protein (MBP) using several different short amino acid linkers and purified via amylose column purification. Short amino acid linkers were cloned into the MBP sea urchin TRBD constructs to facilitate better crystallization of the fusion protein. Future work of this project includes testing telomerase RNA binding affinity to the TRBD constructs and determining the crystal structure of the sea urchin TRBD with bound eCR4/5. Elucidating how eCR4/5 binds to the sea urchin TRBD will provide insights into the evolutionary relationship between eCR4/5 and the pseudoknot/template domain of sea urchin telomerase RNA.
Date Created
2018-05
Agent

Structure and Function of Echinoderm Telomerase RNA

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Description

Telomerase is a ribonucleoprotein (RNP) enzyme that requires an integral telomerase RNA (TR) subunit, in addition to the catalytic telomerase reverse transcriptase (TERT), for enzymatic function. The secondary structures of TRs from the three major groups of species, ciliates, fungi,

Telomerase is a ribonucleoprotein (RNP) enzyme that requires an integral telomerase RNA (TR) subunit, in addition to the catalytic telomerase reverse transcriptase (TERT), for enzymatic function. The secondary structures of TRs from the three major groups of species, ciliates, fungi, and vertebrates, have been studied extensively and demonstrate dramatic diversity. Herein, we report the first comprehensive secondary structure of TR from echinoderms—marine invertebrates closely related to vertebrates—determined by phylogenetic comparative analysis of 16 TR sequences from three separate echinoderm classes. Similar to vertebrate TR, echinoderm TR contains the highly conserved template/pseudoknot and H/ACA domains. However, echinoderm TR lacks the ancestral CR4/5 structural domain found throughout vertebrate and fungal TRs. Instead, echinoderm TR contains a distinct simple helical region, termed eCR4/5, that is functionally equivalent to the CR4/5 domain. The urchin and brittle star eCR4/5 domains bind specifically to their respective TERT proteins and stimulate telomerase activity. Distinct from vertebrate telomerase, the echinoderm TR template/pseudoknot domain with the TERT protein is sufficient to reconstitute significant telomerase activity. This gain-of-function of the echinoderm template/pseudoknot domain for conferring telomerase activity presumably facilitated the rapid structural evolution of the eCR4/5 domain throughout the echinoderm lineage. Additionally, echinoderm TR utilizes the template-adjacent P1.1 helix as a physical template boundary element to prevent nontelomeric DNA synthesis, a mechanism used by ciliate and fungal TRs. Thus, the chimeric and eccentric structural features of echinoderm TR provide unparalleled insights into the rapid evolution of telomerase RNP structure and function.

Date Created
2015-11-23
Agent

The Functional Requirement of Two Structural Domains Within Telomerase RNA Emerged Early in Eukaryotes

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Description

Telomerase emerged during evolution as a prominent solution to the eukaryotic linear chromosome end-replication problem. Telomerase minimally comprises the catalytic telomerase reverse transcriptase (TERT) and telomerase RNA (TR) that provides the template for telomeric DNA synthesis. While the TERT protein

Telomerase emerged during evolution as a prominent solution to the eukaryotic linear chromosome end-replication problem. Telomerase minimally comprises the catalytic telomerase reverse transcriptase (TERT) and telomerase RNA (TR) that provides the template for telomeric DNA synthesis. While the TERT protein is well-conserved across taxa, TR is highly divergent amongst distinct groups of species. Herein, we have identified the essential functional domains of TR from the basal eukaryotic species Trypanosoma brucei, revealing the ancestry of TR comprising two distinct structural core domains that can assemble in trans with TERT and reconstitute active telomerase enzyme in vitro. The upstream essential domain of T. brucei TR, termed the template core, constitutes three short helices in addition to the 11-nt template. Interestingly, the trypanosome template core domain lacks the ubiquitous pseudoknot found in all known TRs, suggesting later evolution of this critical structural element. The template-distal domain is a short stem-loop, termed equivalent CR4/5 (eCR4/5). While functionally similar to vertebrate and fungal CR4/5, trypanosome eCR4/5 is structurally distinctive, lacking the essential P6.1 stem-loop. Our functional study of trypanosome TR core domains suggests that the functional requirement of two discrete structural domains is a common feature of TRs and emerged early in telomerase evolution.

Date Created
2016-07-04
Agent

Prevalent and Distinct Spliceosomal 3 '-end Processing Mechanisms for Fungal Telomerase RNA

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Description

Telomerase RNA (TER) is an essential component of the telomerase ribonucleoprotein complex. The mechanism for TER 3′-end processing is highly divergent among different organisms. Here we report a unique spliceosome-mediated TER 3′-end cleavage mechanism in Neurospora crassa that is distinct

Telomerase RNA (TER) is an essential component of the telomerase ribonucleoprotein complex. The mechanism for TER 3′-end processing is highly divergent among different organisms. Here we report a unique spliceosome-mediated TER 3′-end cleavage mechanism in Neurospora crassa that is distinct from that found specifically in the fission yeast Schizosaccharomyces pombe. While the S. pombe TER intron contains the canonical 5′-splice site GUAUGU, the N. crassa TER intron contains a non-canonical 5′-splice site AUAAGU that alone prevents the second step of splicing and promotes spliceosomal cleavage. The unique N. crassa TER 5′-splice site sequence is evolutionarily conserved in TERs from Pezizomycotina and early branching Taphrinomycotina species. This suggests that the widespread and basal N. crassa-type spliceosomal cleavage mechanism is more ancestral than the S. pombe-type. The discovery of a prevalent, yet distinct, spliceosomal cleavage mechanism throughout diverse fungal clades furthers our understanding of TER evolution and non-coding RNA processing.

Date Created
2015-01-01
Agent

Identification, characterization and evolution of invertebrate telomerase RNA

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Description
Telomerase is a specialized enzyme that adds telomeric DNA repeats to the chromosome ends to counterbalance the progressive telomere shortening over cell divisions. It has two essential core components, a catalytic telomerase reverse transcriptase protein (TERT), and a telomerase RNA

Telomerase is a specialized enzyme that adds telomeric DNA repeats to the chromosome ends to counterbalance the progressive telomere shortening over cell divisions. It has two essential core components, a catalytic telomerase reverse transcriptase protein (TERT), and a telomerase RNA (TR). TERT synthesizes telomeric DNA by reverse transcribing a short template sequence in TR. Unlike TERT, TR is extremely divergent in size, sequence and structure and has only been identified in three evolutionarily distant groups. The lack of knowledge on TR from important model organisms has been a roadblock for vigorous studies on telomerase regulation. To address this issue, a novel in vitro system combining deep-sequencing and bioinformatics search was developed to discover TR from new phylogenetic groups. The system has been validated by the successful identification of TR from echinoderm purple sea urchin Strongylocentrotus purpuratus. The sea urchin TR (spTR) is the first invertebrate TR that has been identified and can serve as a model for understanding how the vertebrate TR evolved with vertebrate-specific traits. By using phylogenetic comparative analysis, the secondary structure of spTR was determined. The spTR secondary structure reveals unique sea urchin specific structure elements as well as homologous structural features shared by TR from other organisms. This study enhanced the understanding of telomerase mechanism and the evolution of telomerase RNP. The system that was used to identity telomerase RNA can be employed for the discovery of other TR as well as the discovery of novel RNA from other RNP complex.
Date Created
2011
Agent