You want to better understand protein disulfide isomerase (PDI) localization and function for generating protein disulfide bonds. You create two different GFP-fusion constructs to express and monitor tagged PDI in the cell, PDI:GFP and GFP:PDI, where GFP sequence has been added to either the C-term or N-term of PDI, respectively. After you transfect different cell populations with the two constructs, you test for PDI transgene protein expression by anti-GFP Western Blot and then examine localization by microscopy. You know that PDI encodes for a 57 kDa protein and GFP expresses at 27 kDa. You are surprised to see that while both protein fusion constructs are expressed at the expected molecular weight and at similar levels, you get different results in localization…!?

Explain what you observe, and why you recovered similar protein expression but distinct localization for the two PDI constructs.

Hunting in the darksome fish rely on senses beyond sight. in the darkness of the marianas trench, a fish called the rattail has an extremely sensitive sense of smell. the fish uses scent, rather than sight, to steer toward food. once it's near food, the rattail uses a special organ on the bottom of its chin to guide itself by feel.marine snowone staple of the deep sea diet is "marine snow," flakes of organic, edible substances that sink down from the upper ocean. animals at the ocean's bottom find sustenance in everything from the bodies of dead creatures to fecal matter. marine snow is diverse enough to support numerous species. for instance, several species of snails and worms feed exclusively on deceased whales.microorganismsthe deep sea is an intricate ecosystem, and even the ocean floor itself plays a part. hydrothermal vents are cracks in the sea floor where erupting magma mixes with ocean water to produce plumes of hot, sulfur-rich chemicals. some microbes can use these chemicals for energy, sustaining their existence and that of the animals who depend on their roles in the deep sea food chain.