From Nikon USA support "The GP-1 has an accessory terminal that supports the use of the MC-DC2 Remote Release." The MC-DC2 is not a 10 pin device, instead it plugs directly into the GP-1. It is sold separately for $25
Most, maybe all, the aftermarket GPS devices also have a connection for a wired cable release. Usually the connection is made using a small stereo plug like the one on many portable audio device headphones. Sometimes this remote is included with the GPS, some times it must be purchased separately. This type of release is available in many camera stores.
Gary in SE Michigan, USA. Nikonians membership - My most important photographic investment, after the camera. D4, D810, D300 (720nm IR conversion), D90, F6, FM3a (black), FM2n (chrome) YashicaMat 124, Graflex Speed Graphic 4x5 My Nikonians Gallery & Our Chapter Gallery