Could I use my Nikor 50mm lens on a Mamiya Sekor 500 TL?

I have a 50mm Nikor lens for my Nikon D90. I have the Mamiya Sekor 500 TL without a lens. Are there any adapters or anything I could use? If there are, which ones?

Added (1). I tried putting it on, it doesn't fit without an adapter of some sort. The lens is too big for the mount.
It's a small circle. It doesn't even look like it would latch on…

Your camera has a pentax screw mount, so a nikon lens to pentax body should work