Using the LRTimelapse presets for Adobe Lightroom I was able to make a 4K resolution time lapse video from the jpeg files from my Canon 5D MK II.
This short video was just a test. I hope to use all of my stills and re-make some of my videos in 4K!!!
This video was Shot with Canon EOS 5D MK II, Canon 16-35mm f2.8L II, 30 second exposures, ISO 3200, WB 4500K
Thanks for looking! 
**You will have to go to the original youtube video page to view in 4K resolution. You can do so by clicking the title of the embeded video ***
Kind of makes you laugh with some of the individuals out there on the net when they ask, why would you need to shoot over 1600 ISO - Sony DSLR's are limited to an ISO of 1600 LOL - you just know they've never filmed anything in the dark before. Perhaps with a 1.2 lenses you can drop the ISO a bit more to filter out potential noise. Shooting with a 2.8 is a bit difficult under low light conditions.
Btw, you might want to go with Vimeo if you want the true quality of your videos to stand out. Even with "1080p" on youtube it's so compressed it looks like it's 720p, therefore I sincerely doubt 4K -youtube Original- will even come close to appearing as you intended. That's why I have accounts on both sites.
