You would have to install the Shared Ownership App on your account as shown in this solution article.
After this is done, there are two steps involved.
1. Map internal groups to a ticket status:
Go to Admin > Ticket fields
Excluding the 4 basic statuses of ticket, map the custom statuses under Mapped Internal Groups.
NOTE: Don't forget to include Customer responded.
2. Set up automation rules to make sure everyone's in the loop:
Go to Admin > Automations > Ticket updates tab > New rule
Set up a new automation rule as below:
When an action is performed by
Involves any of these events
Reply IS sent
On tickets with these properties
Status is NOT > Open OR Waiting on Third party OR Waiting on Sellers team
Perform these actions:
Set status as > OPEN
Send email to Agent > Assigned Agent