Researchers have discovered a group of plant proteins that a

Researchers have discovered a group of plant proteins that are related to the exocyst proteins in yeast (The Plant Cell 20 (2008): 1330). Explain how the following observations made by these researchers suggest that these plant proteins form a tethering complex similar to the exocyst complex of yeast and mammals. Following size fractionation of plant protein extracts, antibodies recognizing each of several different plant exocyst proteins bind to the same high-molecular-weight protein fraction. This observation is consistent with the prediction that the different plant exocyst proteins are associated in a multicarbohydrate complex similar to the exocyst complex of yeast and mammals. This observation is consistent with the prediction that the different plant exocyst proteins are associated in a multiprotein complex similar to the exocyst complex of yeast and mammals. This observation is consistent with the prediction that the different plant exocyst proteins are associated in a multicarbohydrate complex distinct from the exocyst complex of yeast and mammals. This observation is consistent with the prediction that the different plant exocyst proteins are associated in a multiprotein complex distinct from the exocyst complex of yeast and mammals. Part B Mutations in four of the proteins each causes defective pollen germination. A mutation resulting in a defective protein interferes with production of the functional multiprotein complex that is required for vesicle transport and subsequent germination. A mutation resulting in a defective protein interferes with production of the functional multiprotein complex that is required for vesicle-lo-vesicle fusion and subsequent germination. A mutation resulting in a defective protein interferes with production of the functional multiprotein complex that is required for vesicle-to-vesicle fusion and subsequent germination. This observation is consistent with the prediction that the different plant exocyst proteins are associated in a multiprotein complex distinct from the exocyst complex of yeast and mammals.

Solution

The correct answrer is:This observation is consistent with the prediction that the different plant exocyst proteins are associated inna multiprotein complex similar to the exocyst complex of yeast and mammals.

Reason:The protein subunits in the exocyst of yeast and plants is the same only with slight different molecular weights i.e nearly 900 kD in yeast and 750 kD in plants which confirms that plant exocyst also contain subunit similar to subunit of yeast exocyst

Part B.The correct answer is: This observation is consistent with the prediction that the different plant exocyst proteins are associated in a multiprotein complex distinct from the exocyst complex of yeast and mammals.

Reason:The mutations in the four proteins cause defective pollen germination in plants but the interaction between the various subunits of exocyst in plants is different from yeast and mammals and therfore distinct from the exocyst complex of yeast and mammals.