Report by : Gan Yung Chyan
/ KUCINTA SETIA
Image : Malayan horseshoe bat in Phuket. Courtesy of Mammal Watching.
Shi Weifeng, Director of the Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in the First Affiliated Hospital of Shandong First Medical University, Shandong Academy of Medical Sciences and 12 other experts from the People's Republic of China and Australia discovered a new bat coronavirus RmYN02 in Malayan horseshoe bats (Rhinopholus malayanus) and submitted their findings to the journal Current Biology.
According to Shi Weifeng, some areas in RmYN02 are very close to the SARS-CoV-2, and there are also amino acid insertions at the junction of the S1 and S2 subunits of its spike protein (S protein), and the insertion method is very similar to that of SARS-CoV-2. Therefore, although this new bat coronavirus is not the direct ancestor of SARS-CoV-2, this insertion phenomenon in the S protein seems abnormal, but it may be a natural result of the evolution of the Malayan bat coronavirus.
Shi Weifeng's team analyzed 227 bat samples collected in Yunnan Province from May to October 2019, and found a new bat coronavirus RmYN02 in Malayan horseshoe bats. These bats are common in Cambodia, Malaysia, Lao PDR, Myanmar, Thailand, Vietnam, the offshore islands of Singapore and in southwest China.
Weifeng explained, “Since the discovery of bats as the chief host of SARS coronavirus in 2005, the scientific community’s research on bats carrying infectious pathogens has been on the rise, and the phenomenon of abundant RNA viruses including coronaviruses in bats is particularly noticeable."
Shortly after the discovery of the new coronavirus, in early January 2020, the RNA collected from these bat samples was sent to the laboratory for next-generation sequencing of metagenomics.
It is said that from the perspective of the whole genome, the closest relationship with SARS-CoV-2 is the virus RaTG13 previously isolated from bats in Yunnan Province but Wang Yanyi, the Director of the Wuhan Institute of Viology, confirmed last week that Shi Zhengli's team has not obtained and kept a live bat coronavirus of RaTG13, thus rendering the viral genome of SARS-CoV-2 artificial.
Parts of the newly discovered bat coraonavirus RmYN02 include the longest coding region 1ab in the entire genome, and the RNA overlap of this region of RmYN02 and RaTG13 reaches 97.2%. However, the researchers pointed out that there is a segment of the new coronavirus genome used to encode the key receptor binding domain that binds to the human ACE2 receptor, which is conducive to its infection of human host cells; and this coding region of the RmYN02 virus is similar to SARS-CoV-2 but it is not likely to infect humans.
The most critical similarity between RmYN02 and SARS-CoV-2 is that there is also an amino acid insertion phenomenon at the junction of the two subunits of its spike protein (S protein). Previous research on SARS-CoV-2 found that 4 amino acids were inserted at the junction of S1 and S2 of its spike protein. This phenomenon is unique to this phenomenon and is common among all new coronaviruses that have been sequenced so far. The insertion phenomenon in the RmYN02 virus is different from that of SARS-CoV-2, which indicates that the insertion events of the two are independent of each other. This time a similar virus was found in another virus in another bat species, which strongly suggests that this phenomenon occurred under natural conditions. "This study proves that although this type of insertion phenomenon may seem unusual at first, it may actually originate from the natural variation of bat coronavirus." Shi Weifeng said.
Weifeng also pointed out, "This study provides us with more clues to explore the evolutionary origin of novel coronavirus. Neither RaTG13 nor RmYN02 is the direct ancestor of SARS-CoV-2, because these two viruses still have great evolutionary differences from SARS-CoV-2. But the results of our research at least clearly confirmed this: To find a virus that is more closely related to SARS-CoV-2, or even to pull out its direct ancestors, the most promising way is to expand the sampling analysis of wild animal species so that scientists can have a deeper understanding of how this virus spread to humans.
Ref :
Shi Weifeng etal., A Novel Bat Coronavirus Closely related to SARS-CoV-2 contains Natural Insertions at the S1/S2 Cleavage Site of the Spike Protein, Current Biology, http://doi.org/10.1016/j.cub.2020.05.023
/ KUCINTA SETIA
Image : Malayan horseshoe bat in Phuket. Courtesy of Mammal Watching.
Shi Weifeng, Director of the Laboratory of Etiology and Epidemiology of Emerging Infectious Diseases in the First Affiliated Hospital of Shandong First Medical University, Shandong Academy of Medical Sciences and 12 other experts from the People's Republic of China and Australia discovered a new bat coronavirus RmYN02 in Malayan horseshoe bats (Rhinopholus malayanus) and submitted their findings to the journal Current Biology.
According to Shi Weifeng, some areas in RmYN02 are very close to the SARS-CoV-2, and there are also amino acid insertions at the junction of the S1 and S2 subunits of its spike protein (S protein), and the insertion method is very similar to that of SARS-CoV-2. Therefore, although this new bat coronavirus is not the direct ancestor of SARS-CoV-2, this insertion phenomenon in the S protein seems abnormal, but it may be a natural result of the evolution of the Malayan bat coronavirus.
Shi Weifeng's team analyzed 227 bat samples collected in Yunnan Province from May to October 2019, and found a new bat coronavirus RmYN02 in Malayan horseshoe bats. These bats are common in Cambodia, Malaysia, Lao PDR, Myanmar, Thailand, Vietnam, the offshore islands of Singapore and in southwest China.
Weifeng explained, “Since the discovery of bats as the chief host of SARS coronavirus in 2005, the scientific community’s research on bats carrying infectious pathogens has been on the rise, and the phenomenon of abundant RNA viruses including coronaviruses in bats is particularly noticeable."
Shortly after the discovery of the new coronavirus, in early January 2020, the RNA collected from these bat samples was sent to the laboratory for next-generation sequencing of metagenomics.
It is said that from the perspective of the whole genome, the closest relationship with SARS-CoV-2 is the virus RaTG13 previously isolated from bats in Yunnan Province but Wang Yanyi, the Director of the Wuhan Institute of Viology, confirmed last week that Shi Zhengli's team has not obtained and kept a live bat coronavirus of RaTG13, thus rendering the viral genome of SARS-CoV-2 artificial.
Parts of the newly discovered bat coraonavirus RmYN02 include the longest coding region 1ab in the entire genome, and the RNA overlap of this region of RmYN02 and RaTG13 reaches 97.2%. However, the researchers pointed out that there is a segment of the new coronavirus genome used to encode the key receptor binding domain that binds to the human ACE2 receptor, which is conducive to its infection of human host cells; and this coding region of the RmYN02 virus is similar to SARS-CoV-2 but it is not likely to infect humans.
The most critical similarity between RmYN02 and SARS-CoV-2 is that there is also an amino acid insertion phenomenon at the junction of the two subunits of its spike protein (S protein). Previous research on SARS-CoV-2 found that 4 amino acids were inserted at the junction of S1 and S2 of its spike protein. This phenomenon is unique to this phenomenon and is common among all new coronaviruses that have been sequenced so far. The insertion phenomenon in the RmYN02 virus is different from that of SARS-CoV-2, which indicates that the insertion events of the two are independent of each other. This time a similar virus was found in another virus in another bat species, which strongly suggests that this phenomenon occurred under natural conditions. "This study proves that although this type of insertion phenomenon may seem unusual at first, it may actually originate from the natural variation of bat coronavirus." Shi Weifeng said.
Weifeng also pointed out, "This study provides us with more clues to explore the evolutionary origin of novel coronavirus. Neither RaTG13 nor RmYN02 is the direct ancestor of SARS-CoV-2, because these two viruses still have great evolutionary differences from SARS-CoV-2. But the results of our research at least clearly confirmed this: To find a virus that is more closely related to SARS-CoV-2, or even to pull out its direct ancestors, the most promising way is to expand the sampling analysis of wild animal species so that scientists can have a deeper understanding of how this virus spread to humans.
Ref :
Shi Weifeng etal., A Novel Bat Coronavirus Closely related to SARS-CoV-2 contains Natural Insertions at the S1/S2 Cleavage Site of the Spike Protein, Current Biology, http://doi.org/10.1016/j.cub.2020.05.023
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