I am not a research nurse (I hope to be!). I was a research assistant in in the academic setting for 3 years in basic sciences/non-human studies before becoming a nurse. So I'll give you what little insight I have.
The PI, principle investigator, of a study is usually a Phd or in medical studies, an MD. I believe that in medical studies, please someone correct me if I'm wrong, the PI needs to have the scope of practice/license to oversee patients/presciptive authority/etc that BSN's or RN's don't have. That's why you won't usually find nurses as authors on research papers in your areas of interest. Now I'm not sure how it works with APRNs. Nurses do have scope of practice over nursing care (i hope so!) and that's why nurses are often the authors of such study papers. In the academic setting, the PI (in my case a Phd) was usually the person who wrote the grant proposal and finalized the study paper for publication. However as a lab tech, my name was included on a few abstracts submitted to conferences. He did alot of the important paperwork/documentation, and I did alot of daily grind work.
However, if you are interested in medical studies (i.e. derma and skin pharm), you don't have to be an MD to participate in it! Many people work with the PI to conduct a successful study, RNs, lab techs, biostaticians, etc. From what I've seen of shadowing a few research coordinators, they do a great deal of the work!
Anyway, I hope this helped and didn't confuse. Hopefully some current research nurses/coordinators will chime in with some better info!