scholarly journals Prokaryotic cell surface biopolymers: bioinformatic analysis

Author(s):  
S. Yu. Shchyogolev ◽  
G. L. Burygin ◽  
M. G. Pyatibratov

Using the example of a number of representatives of bacteria and archaea, the structure of their cell surface biopolymers is considered, taking into account post-translational modifications of proteins and contemporary views on the features of protein folding.

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Sally Badawi ◽  
Bassam R. Ali

AbstractWith the emergence of the novel coronavirus SARS-CoV-2 since December 2019, more than 65 million cases have been reported worldwide. This virus has shown high infectivity and severe symptoms in some cases, leading to over 1.5 million deaths globally. Despite the collaborative and concerted research efforts that have been made, no effective medication for COVID-19 (coronavirus disease-2019) is currently available. SARS-CoV-2 uses the angiotensin-converting enzyme 2 (ACE2) as an initial mediator for viral attachment and host cell invasion. ACE2 is widely distributed in the human tissues including the cell surface of lung cells which represent the primary site of the infection. Inhibiting or reducing cell surface availability of ACE2 represents a promising therapy for tackling COVID-19. In this context, most ACE2–based therapeutic strategies have aimed to tackle the virus through the use of angiotensin-converting enzyme (ACE) inhibitors or neutralizing the virus by exogenous administration of ACE2, which does not directly aim to reduce its membrane availability. However, through this review, we present a different perspective focusing on the subcellular localization and trafficking of ACE2. Membrane targeting of ACE2, and shedding and cellular trafficking pathways including the internalization are not well elucidated in literature. Therefore, we hereby present an overview of the fate of newly synthesized ACE2, its post translational modifications, and what is known of its trafficking pathways. In addition, we highlight the possibility that some of the identified ACE2 missense variants might affect its trafficking efficiency and localization and hence may explain some of the observed variable severity of SARS-CoV-2 infections. Moreover, an extensive understanding of these processes is necessarily required to evaluate the potential use of ACE2 as a credible therapeutic target.


1989 ◽  
Vol 92 (4) ◽  
pp. 633-642
Author(s):  
J.K. Burkhardt ◽  
Y. Argon

The appearance of newly synthesized glycoprotein (G) of vesicular stomatitis virus at the surface of infected BHK cells is inhibited reversibly by treatment with carbonylcyanide m-chlorophenylhydrazone (CCCP). Under the conditions used, CCCP treatment depleted the cellular ATP levels by 40–60%, consistent with inhibition of transport at energy-requiring stages. The G protein that accumulates in cells treated with CCCP is heterogeneous. Most of it is larger than the newly synthesized G protein, is acylated with palmitic acid, and is resistant to endoglycosidase H (Endo H). Most of the arrested G protein is also sensitive to digestion with neuraminidase, indicating that it has undergone at least partial sialylation. A minority of G protein accumulates under these conditions in a less-mature form, suggesting its inability to reach the mid-Golgi compartment. The oligosaccharides of this G protein are Endo-H-sensitive and seem to be partly trimmed. Whereas sialylated G protein was arrested intracellularly, fucose-labelled G protein was able to complete its transport to the cell surface, indicating that a late CCCP-sensitive step separates sialylation from fucosylation. These post-translational modifications indicate that G protein can be transported as far as the trans-Golgi in the presence of CCCP and is not merely arrested in the endoplasmic reticulum.


2020 ◽  
Vol 103 (4) ◽  
pp. 003685042096431
Author(s):  
Suzanne Forrest ◽  
Martin Welch

Protein secretion is almost universally employed by bacteria. Some proteins are retained on the cell surface, whereas others are released into the extracellular milieu, often playing a key role in virulence. In this review, we discuss the diverse types and potential functions of post-translational modifications (PTMs) occurring to extracellular bacterial proteins.


Nature ◽  
1978 ◽  
Vol 273 (5659) ◽  
pp. 250-250
Author(s):  
H. J. Rogers

2021 ◽  
Author(s):  
Subhash Solanki ◽  
Poonam Kashyap ◽  
Vijay Kumar ◽  
Martina Pukhrambam ◽  
Sachinandan De ◽  
...  

Abstract Background: The male reproductive specific class-A β-defensins are adsorbed on sperm surface and enrich sperm functioning thus considered vital for maintaining male fertility. The primate DEFB129 play role in sperm maturation, motility, and fertilization but its contribution to bovine fertility is still unexplored.Method: RLM-RACE and RT-qPCR approaches were used to characterize and expression analysis of Indian cattle BBD129 gene. The polymorphism analysis of the BBD129 gene was done by PCR, sequencing, and absolute RT-qPCR on sperm gDNA from distinct fertility cattle bulls. Bioinformatic analysis was performed to understand the structural and functional implications of SNP on BBD129 protein.Results: The complete coding sequence of the BBD129 gene consists of 582 bp mRNA including UTRs and conserves all beta-defensin-like characteristics. Sequencing results revealed two conserved non-synonymous T169G (rs378737321, S57A) and A329G (rs383285978, N110S) SNPs in the functional protein-coding exon. Based on SNP position and linkage, BBD129 gene haplotypes were categorized into four groups: TA haplotype (169T & 329A), GA haplotype (T169G polymorphism), TG haplotype (A329G polymorphism), and GG haplotype (when T169G & A329G polymorphisms present together). The frequencies distributions of BBD129 haplotypes in the high fertile group (n=105 clones) were: TA (71.42%), GA (1.90%), TG (2.8%), and GG (24.76%), while in the low fertile group of bulls, the frequencies distributions of observed BBD129 haplotypes (n=149 clones) were: TA (36.24%), GA (0%), TG (2.68%), and GG (61.07%). The distributions of TA haplotype were majorly distributed in bulls with a high conception rate (P=0.5256) while double mutated GG haplotype was significantly more abundant in bulls with a lower conception rate (P=0.0001). BBD129 exist as a single-copy gene in the bovine genome and found higher expression in the corpus-epididymis region. Bioinformatic analyses found nsSNPs as neutral and non-deleterious but their structural-distorter could result in altered mRNA secondary structure, protein conformations decreased protein stability, and compromised biological functionalities. The polymorphisms resulted in altered O-glycosylations (deletion S57A and insertion N110S) and an increase in phosphorylations (52T-Threonine and 110S-Serine) post-translational-modifications.Conclusion: BBD129 gene polymorphism could be associated with the fertility performance of cattle bulls.


Author(s):  
Sally Badawi ◽  
Bassam Ali

With the emergence of the novel corona virus SARS-CoV-2 since December 2019, more than 43 million cases have been reported worldwide. This virus has shown high infectivity and severe symptoms in some cases leading to over 1 million deaths globally. Despite the collaborative and concerted research efforts that has been made, no effective treatment for COVID-19 (corona virus disease-2019) is currently available. SARS-CoV-2 uses the angiotensin converting enzyme 2 (ACE2) as an initial mediator for viral attachment and host cell invasion. ACE2 is widely distributed in human tissues including the cell surface of lung cells which represent the primary site of the infection. Inhibiting or reducing cell surface availability of ACE2 represents a promising therapy for tackling COVID-19. In this context, most ACE2–based therapeutic strategies have aimed to achieve this through the use of angiotensin converting enzyme (ACE) inhibitors or neutralizing the virus by exogenous administration of ACE2. However, through this review, we present another perspective focusing on the subcellular localization and trafficking of ACE2. Membrane targeting of ACE2, shedding and its cellular trafficking pathways including internalization are not well elucidated. Therefore, hereby we present an overview on the fate of newly synthesized ACE2, its post translational modifications, what is known of its trafficking pathways. In addition, we highlight the possibility that some of the identified ACE2 missense variants might affect its trafficking efficiency and localization and hence may explain some of the observed variable severity of SARS-CoV-2 infections. Extensive understanding of these processes is necessary to evaluate the potential use of ACE2 as a credible therapeutic target.


2010 ◽  
Vol 5 (1) ◽  
pp. 1 ◽  
Author(s):  
Vivek Anantharaman ◽  
L Aravind

1995 ◽  
Vol 305 (1) ◽  
pp. 307-313 ◽  
Author(s):  
A Jardim ◽  
V Funk ◽  
R M Caprioli ◽  
R W Olafson

A novel membrane molecule, previously observed to be co-isolated with lipophosphoglycan and called lipophosphoglycan-associated protein, has been detected in Leishmania donovani promastigotes and amastigotes. This kinetoplastid membrane protein (KMP-11) has been purified by preparative SDS/PAGE after organic solvent extraction of promastigote membranes. Isoelectric-focusing experiments indicated that this was an acidic protein with an isoelectric point of 4.8. Immunoblot analysis of subcellular fractions, together with 125I-labelling experiments, showed this molecule to be associated with the promastigote cell surface membrane. KMP-11 was expressed at a copy number similar to that of lipophosphoglycan (1 x 10(6)-2 x 10(6) molecules per cell), making this glycoprotein one of the major features on the parasite cell surface. The primary structure, less a blocked N-terminal region, was determined by automated Edman degradation of peptides derived from CNBr or enzymic fragmentation. Several post-translational modifications were also found during these studies, including an O-linked oligosaccharide and an NG-monomethylarginine functionality which was verified by m.s. Finally, a set of sequential synthetic peptides was made based on the established partial sequence allowing structural determination of two distinct antibody-binding sites for the monoclonal antibodies L98 and L157.


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