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SARS-CoV-2 spike protein might explain why the Delta variant of Covid-19 has spread so swiftly across the world, say researchers

A key amino-acid mutation in the SARS-CoV-2 spike protein might explain why the Delta variant of Covid-19 has spread so swiftly across the world, say researchers. SARS-CoV-2 Delta variant has rapidly replaced the Alpha variant around the world. According to epidemiological studies, the Delta variant, first identified in India in late 2020, is at least 40 per cent more transmissible than the Alpha variant, first identified in the UK, last year.

However, the mechanism that drives this global replacement has not been defined yet.

The study, yet to be peer-reviewed and posted on pre-print server bioRxiv, showed how P681R mutation in the Delta spike plays a key role in the replacement of Alpha-to-Delta variant. "Delta SARS-CoV-2 efficiently outcompeted the Alpha variant in human lung epithelial cells and primary human airway tissues," wrote researchers from the University of Texas and others in the abstract.

The P681R mutation falls within an intensely studied region of the spike protein called the furin cleavage site, Nature reported.

The short string of amino acids P681R is associated with heightened infectivity in other viruses such as influenza. However, it has not previously been found in sarbecoviruses -- the family of coronaviruses to which SARS-CoV-2 belongs. "The key hallmark of Delta is that transmissibility seems to be ramping up to the next notch," Pei-Yong Shi, a virologist at the University of Texas's Medical Branch in Galveston was quoted as saying.

"We thought Alpha was pretty bad, very good at spreading. This one seems to be even more," Shi added.

Further, the presence of P681R mutation enabled the Delta variant to rapidly outcompete the Alpha variant, in cultured human-airway epithelial cells infected with equal numbers of Delta and Alpha viral particles. However, when the team eliminated the P681R mutation, Delta's advantage waned.

The study also suggested that the mutation also speeds up the spread of SARS-CoV-2 from cell to cell, Nature report said.

Researchers at the University of Tokyo found that spike proteins bearing the P681R mutation fuses with the plasma membranes of uninfected cells -- a key step in infection -- almost three times faster than the spike proteins that lack the change. The team suggests that the P681R mutation may not be alone, and further studies are needed to examine other mutations in the spike protein of Delta to understand its swift transmission.

(Article originally published at IANSlife)IANS/SS

Keywords: health, covid, tokyo, delta, variant



Kashmir's natural splendour, with its beautiful valleys and towering mountains, is really unlike anywhere.

Along with the undeniable natural beauty, the Kashmir valley has developed a reputation for adventurous activities like trekking, hiking, and river rafting. Kashmir has maintained its charm, allowing us to time-travel into beautiful destinations which make one forget about the stress and worries of life. The hikes in Kashmir offer adventurers to go on a self-discovery trip through nature's lap over the mountains while taking in the breathtaking scenery that surrounds them on their journey. In addition to the hikes, there are many thrilling adventure activities, like rock climbing, rope climbing, etc. Trekking across the region of mountains and lakes will allow you to experience living in the "Paradise on Earth," and you wouldn't want to return to your regular life after that.

The following are some of the finest hiking destinations in Kashmir:

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Pind Daan at Jagannath Ghat, Kolkata.

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It is believed that from the very first day till the last day, the unhappy souls of the deceased return to the Earth to see their family members. So, in order to ensure that the dead attain Moksha, i.e. to get liberation, family members of these souls quench their thirst and satisfy their hunger by performing the Pind Daan, which includes offering food consisting of cooked rice and black sesame seeds. The literal meaning of Pind Daan is the act of satisfying those who no longer exist physically.

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It stands testament to the past, in terms of the diversity of flora it houses. Bangalore traffic in the recent past has grown into a menace, but the stretch between MG Road and Cubbon Park is always a pleasurable place to stop and wait for the signal to turn green. The gust of wind that blows here, and the smell of mud, coupled with floral scents instantly transports citizens to Old Bangalore, where the weather was fine, and the trees loomed over roads with thick canopies that did not even allow rainwater to penetrate. Cubbon Park is also a historical site, and one of the few remaining monuments of colonial heritage in Central Bangalore. It houses many statues and among them, the most famous is that of Queen Victoria, which faces the St. Mark's Square.

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