Go to the UniProt page and use the search bar (at the very top) to search for the gene name CFTR Click on the entry number for the mouse version of the protein (entry P26361). (The mouse entry is a bit more complete than the human entries in terms of seeing structural details.) You will focus on the sections called Function Pathology and Biotech Expression and Structure Function: a Fill in the blanks: Epithelial channel that plays an important role in the regulation of epithelial transport and fluid homeostasis (PubMed 26823428). Mediates the transport of across the cell membrane (PubMed 20231442 PubMed 22265409) Channel activity is coupled to _ hydrolysis. b. Based on your knowledge of transport across cell membranes is the quoted material above describing a passive transport event or an active transport event? How do you know? Pathology and Biotech: c Mice have been created which have homozygous disruptions of the CFTR gene. The phenotypes of these mice are described in this section. Under Mutagenesis there is a list. Which amino acid position (a number) was targeted for disruption in every case? Does this connect to something you leared in question 3 (above)? Why does it make sense that they might try to create this specific mutation in mice order to study the effects? (Yes these are mice and question 3 is referring to humans but what do you know about Mus musculus from Chapter 1 of this course?) Expression: Under Tissue Specificity there are three isoforms described. d. Relating to lecture matenal from Chapter 11. what is an isoform? How is it related to the concept of alternative splicing of mRNA? e. For each isoform list the tissues that express that protein: Isoform 1: Isoform 2 Isoform 3 Structure: For fun look at the three-dimensional model of the CFTR protein Notice that you can click and drag the model to view it from different angles. This model shows multiple subunits (each tertiary structure is shown in a different color). The secondary structures are visible within each tertiary structure. There is also a linear key showing the protein laid out from amino to carboxyl end (N to C) with the regions of secondary structures marked (No question to answer here)
