Has Lupin Taught before?

[Heather Moore]

No: HPFGUIDX 29405

--- In HPforGrownups at y..., "Aurora Mendelsohn" <amendels at l...> wrote:
> In PoA, on the train on the way to Hogwarts, Lupin's bag is describes as being frayed and worn out with a worn out name "*
> Professor* R.J. Lupin" (IIRC). Isn't this his first time as a professor at Hogwarts? How can the name on his bag be worn out if the 
> title professor is new to him? Did I miss something? Has he taught before ( at Hogwarts before Harry'stime or somewhwere else)?
> 
> Aurora

PoA is the book I most have to re-read, as I only had borrowed it for a limited time (the duration of a plane flight) and had to skim chunks of it. So this may come across as a silly suggestion, but I plead ignorance!!

 -- Is it possible that Lupin was the DADA professor during the period Quirrell was on his vampire-slaying, parasite-hosting, not-terribly-restful sabbatical?