1
|
Anyaogu DC, Hansen AH, Hoof JB, Majewska NI, Contesini FJ, Paul JT, Nielsen KF, Hobley TJ, Yang S, Zhang H, Betenbaugh M, Mortensen UH. Glycoengineering of Aspergillus nidulans to produce precursors for humanized N-glycan structures. Metab Eng 2021; 67:153-163. [PMID: 34174425 DOI: 10.1016/j.ymben.2021.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 04/15/2021] [Accepted: 06/14/2021] [Indexed: 02/08/2023]
Abstract
Filamentous fungi secrete protein with a very high efficiency, and this potential can be exploited advantageously to produce therapeutic proteins at low costs. A significant barrier to this goal is posed by the fact that fungal N-glycosylation varies substantially from that of humans. Inappropriate N-glycosylation of therapeutics results in reduced product quality, including poor efficacy, decreased serum half-life, and undesirable immune reactions. One solution to this problem is to reprogram the glycosylation pathway of filamentous fungi to decorate proteins with glycans that match, or can be remodeled into, those that are accepted by humans. In yeast, deletion of ALG3 leads to the accumulation of Man5GlcNAc2 glycan structures that can act as a precursor for remodeling. However, in Aspergilli, deletion of the ALG3 homolog algC leads to an N-glycan pool where the majority of the structures contain more hexose residues than the Man3-5GlcNAc2 species that can serve as substrates for humanized glycan structures. Hence, additional strain optimization is required. In this report, we have used gene deletions in combination with enzymatic and chemical glycan treatments to investigate N-glycosylation in the model fungus Aspergillus nidulans. In vitro analyses showed that only some of the N-glycan structures produced by a mutant A. nidulans strain, which is devoid of any of the known ER mannose transferases, can be trimmed into desirable Man3GlcNAc2 glycan structures, as substantial amounts of glycan structures appear to be capped by glucose residues. In agreement with this view, deletion of the ALG6 homolog algF, which encodes the putative α-1,3- glucosyltransferase that adds the first glucose residue to the growing ER glycan structure, dramatically reduces the amounts of Hex6-7HexNAc2 structures. Similarly, these structures are also sensitive to overexpression of the genes encoding the heterodimeric α-glucosidase II complex. Without the glucose caps, a new set of large N-glycan structures was formed. Formation of this set is mostly, perhaps entirely, due to mannosylation, as overexpression of the gene encoding mannosidase activity led to their elimination. Based on our new insights into the N-glycan processing in A. nidulans, an A. nidulans mutant strain was constructed in which more than 70% of the glycoforms appear to be Man3-5GlcNAc2 species, which may serve as precursors for further engineering in order to create more complex human-like N-glycan structures.
Collapse
Affiliation(s)
- Diana Chinyere Anyaogu
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 223, 2800 kgs, Lyngby, Denmark
| | - Anders Holmgaard Hansen
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet Building 220, Lyngby, Denmark
| | - Jakob Blæsbjerg Hoof
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 223, 2800 kgs, Lyngby, Denmark
| | - Natalia I Majewska
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Fabiano Jares Contesini
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 223, 2800 kgs, Lyngby, Denmark
| | - Jackson T Paul
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Kristian Fog Nielsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 223, 2800 kgs, Lyngby, Denmark
| | - Timothy John Hobley
- National Food Institute, Technical University of Denmark, Søltofts Plads, Building 222, 2800 Kgs, Lyngby, Denmark
| | - Shuang Yang
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Hui Zhang
- Department of Pathology, Johns Hopkins School of Medicine, Baltimore, MD, 21205, USA
| | - Michael Betenbaugh
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.
| | - Uffe Hasbro Mortensen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 223, 2800 kgs, Lyngby, Denmark.
| |
Collapse
|
2
|
Wang Q, Wang T, Yang S, Sha S, Wu WW, Chen Y, Paul JT, Shen RF, Cipollo JF, Betenbaugh MJ. Metabolic engineering challenges of extending N-glycan pathways in Chinese hamster ovary cells. Metab Eng 2020; 61:301-314. [PMID: 32663509 DOI: 10.1016/j.ymben.2020.06.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 05/28/2020] [Accepted: 06/11/2020] [Indexed: 12/22/2022]
Abstract
In mammalian cells, N-glycans may include multiple N-acetyllactosamine (poly-LacNAc) units that can play roles in various cellular functions and properties of therapeutic recombinant proteins. Previous studies indicated that β-1,3-N-acetylglucosaminyltransferase 2 (B3GNT2) and β-1,4-galactotransferase 1 (B4GALT1) are two of the primary glycosyltransferases involved in generating LacNAc units. In the current study, knocking out sialyltransferase genes slightly enhanced the LacNAc content (≥4 repeats per glycan) on recombinant EPO protein. Next, the role of single and dual-overexpression of B3GNT2 and B4GALT1 was explored in recombinant EPO-expressing Chinese hamster ovary (CHO) cells. While overexpression of B4GALT1 slightly enhanced the levels of large glycans on recombinant EPO, overexpression of B3GNT2 in EPO-expressing CHO cells significantly decreased the recombinant EPO LacNAc content, resulting in N-glycans terminating primarily with GlcNAc structures, a limited number of Gals, and nearly undetectable sialylation, which was also observed in sialyltransferases knock-out-B3GNT2 overexpression cell lines. Considering the nature of the binding domain motifs present on B3GNT2, which evolved from β1,3-galactosyltransferases, its overexpression may have competed and inhibited endogenous β1,4-galactosyltransferases for exposed GlcNAc residues on the N-glycans, resulting in premature termination of many N-glycans at GlcNAc. Furthermore, B3GNT2 overexpression enhanced intracellular UDP-GlcNAc and CMP-Neu5Ac content while slightly lowering UDP-Gal content. The presence of a sink for UDP-GlcNAc in the form of B3GNT2 with no disposition may have also elevated the intracellular levels of this nucleotide as well as its downstream product, CMP-Neu5Ac. Furthermore, we were unable to overexpress B4GALT1 at either the transcriptional or translational levels following initial B3GNT2 expression. Expression of B3GNT2 following initial expression of B4GALT1 was also problematic in that transcriptional and translational analysis indicated the accumulation of truncated B3GNT2 missing a section of the B3GNT2 trans-Golgi lumen domain while transmembrane and cytoplasmic domains were present. Given that glycosylation is a very complex intra-network process, the addition of one or more recombinant glycosyltransferases may have an unexpected influence on the expression and activities of glycosyltransferases, which can disrupt the nucleotide sugar levels and lead to unexpected modifications of the resulting N-glycan patterns.
Collapse
Affiliation(s)
- Qiong Wang
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Tiexin Wang
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Shuang Yang
- Laboratory for Bacterial Polysaccharides, Division of Bacterial, Parasitic and Allergenic Products (DBPAP), Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Sha Sha
- Center for Biomedical Innovation, Massachusetts Institute of Technology (MIT), Cambridge, MA, 02139, USA
| | - Wells W Wu
- Facility for Biotechnology Resources, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Yiqun Chen
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Jackson T Paul
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Rong-Fong Shen
- Facility for Biotechnology Resources, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - John F Cipollo
- Laboratory for Bacterial Polysaccharides, Division of Bacterial, Parasitic and Allergenic Products (DBPAP), Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Michael J Betenbaugh
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
3
|
Paul JT, Singh AK, Dong Z, Zhuang H, Revard BC, Rijal B, Ashton M, Linscheid A, Blonsky M, Gluhovic D, Guo J, Hennig RG. Computational methods for 2D materials: discovery, property characterization, and application design. J Phys Condens Matter 2017; 29:473001. [PMID: 29022886 DOI: 10.1088/1361-648x/aa9305] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The discovery of two-dimensional (2D) materials comes at a time when computational methods are mature and can predict novel 2D materials, characterize their properties, and guide the design of 2D materials for applications. This article reviews the recent progress in computational approaches for 2D materials research. We discuss the computational techniques and provide an overview of the ongoing research in the field. We begin with an overview of known 2D materials, common computational methods, and available cyber infrastructures. We then move onto the discovery of novel 2D materials, discussing the stability criteria for 2D materials, computational methods for structure prediction, and interactions of monolayers with electrochemical and gaseous environments. Next, we describe the computational characterization of the 2D materials' electronic, optical, magnetic, and superconducting properties and the response of the properties under applied mechanical strain and electrical fields. From there, we move on to discuss the structure and properties of defects in 2D materials, and describe methods for 2D materials device simulations. We conclude by providing an outlook on the needs and challenges for future developments in the field of computational research for 2D materials.
Collapse
Affiliation(s)
- J T Paul
- Department of Materials Science and Engineering, University of Florida, Gainesville, Fl 32611, United States of America
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Abstract
Post-translational modification of proteins with carbohydrates shapes their localization and function. This SnapShot presents the core pathways from different organisms that install these complex and highly variable structures.
Collapse
Affiliation(s)
- Cheng-Yu Chung
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Natalia I Majewska
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Qiong Wang
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jackson T Paul
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Michael J Betenbaugh
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
| |
Collapse
|
5
|
Affiliation(s)
- J T Paul
- Department of Neurosciences, Harbin Clinic, 958A Joe Frank Harris Pkwy, Suite 105, Cartersville, GA 30121, USA
| |
Collapse
|
6
|
Mai S, Hanley-Hyde J, Rainey GJ, Kuschak TI, Paul JT, Littlewood TD, Mischak H, Stevens LM, Henderson DW, Mushinski JF. Chromosomal and extrachromosomal instability of the cyclin D2 gene is induced by Myc overexpression. Neoplasia 1999; 1:241-52. [PMID: 10935479 PMCID: PMC1508077 DOI: 10.1038/sj.neo.7900030] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/1999] [Accepted: 05/25/1999] [Indexed: 11/08/2022]
Abstract
We examined the expression of cyclins D1, D2, D3, and E in mouse B-lymphocytic tumors. Cyclin D2 mRNA was consistently elevated in plasmacytomas, which characteristically contain Myc-activating chromosome translocations and constitutive c-Myc mRNA and protein expression. We examined the nature of cyclin D2 overexpression in plasmacytomas and other tumors. Human and mouse tumor cell lines that exhibited c-Myc dysregulation displayed instability of the cyclin D2 gene, detected by Southern blot, fluorescent in situ hybridization (FISH), and in extrachromosomal preparations (Hirt extracts). Cyclin D2 instability was not seen in cells with low levels of c-Myc protein. To unequivocally demonstrate a role of c-Myc in the instability of the cyclin D2 gene, a Myc-estrogen receptor chimera was activated in two mouse cell lines. After 3 to 4 days of Myc-ER activation, instability at the cyclin D2 locus was seen in the form of extrachromosomal elements, determined by FISH of metaphase and interphase nuclei and of purified extrachromosomal elements. At the same time points, Northern and Western blot analyses detected increased cyclin D2 mRNA and protein levels. These data suggest that Myc-induced genomic instability may contribute to neoplasia by increasing the levels of a cell cycle-regulating protein, cyclin D2, via intrachromosomal amplification of its gene or generation of extrachromosomal copies.
Collapse
Affiliation(s)
- S Mai
- Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Abstract
We report on a Samoan man with dysphagia, voice hoarseness, facial erythema, and edema. Neurologic examination revealed hypesthesia at the site of the facial rash, enlarged auricular nerves, a right facial palsy, decreased gag reflexes, and voice hoarseness. Laryngoscopic examination showed paralysis of the left vocal cord, and a barium swallow revealed a possible compressive lesion. A skin biopsy specimen was diagnostic of tuberculoid leprosy. This patient has an unusual case of leprosy with multiple cranial neuropathies.
Collapse
Affiliation(s)
- J T Paul
- Department of Family Practice, Martin Army Community Hospital, Ft. Benning, Ga
| | | | | | | | | |
Collapse
|
8
|
Presley SJ, Johnson CA, Paul JT, Ranke EJ. A short method for blood glucose determination. IMJ Ill Med J 1965; 128:629-32. [PMID: 4379036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|