Mguarino22

SChadda Feedback on GLUT4 Article:

Overall I thought these sections were very informative! There were a few points that were a little unclear to me, which I have highlighted below. Overall really great job! And let me know if there is anything in my notes that requires clarification.

Skeletal Muscle:

• Clarifying the term "element of GLUT4". I was a little confused as to what exactly the definition of an element is, perhaps a subclass of Glut4 transporter?
• I am having trouble understanding how positive and negative element concentrations are different during muscle contraction and exercise. I guess I am sort of confused as to which elements are active during which processes, and how exercise is different than muscle contraction alone.
• I was also wondering if this positive and negative element differentiation was specific to skeletal muscle or is an important term to understand for Glut4 transport in all tissues. If this is the case, I would maybe suggest providing a little bit of background information about general Glut4 function in tissues before diving into the specifics of each tissue type.

Cardiac Muscle:

• Perhaps stating explicitly that Glut4 is primarily used when there is high activity, but otherwise, I think this section is pretty good.

Adipose Tissue:

• The information provided in this section, especially this particular quote: "As we eat and glucose levels increase, insulin is released from the pancreas and into the blood stream. Increased insulin levels cause the uptake of glucose into the cells. GLUT4 is stored in the cell in transport vesicles, and is quickly incorporated into the plasma membrane of the cell when insulin binds to membrane receptors." , I feel could be useful for understanding Glut4 tissue function in general. Perhaps creating an intro section that goes over this information and Glut4 elements may be helpful in providing clarity to the rest of the sections.

Some other notes:

• There is a section on muscle contraction at the bottom of the article that could maybe be incorporated into the sections on tissues.
• As I was reading, I was wondering how prolonged exercise was different then muscle contraction, as your muscles contract when one is exercising. Is the distinction between differences in contraction during exercise and contraction at rest? It was just something I was thinking about, I am not sure how relevant it is to Glut4.

Links to articles of interest:

GLUT4

http://www.nature.com/nature/journal/v409/n6821/full/409729a0.html

http://www.nature.com/nrm/journal/v3/n4/full/nrm782.html

http://www.sciencedirect.com/science/article/pii/S1550413107000678

http://www.sciencedirect.com/science/article/pii/S0169328X02004874

http://www.pnas.org/content/92/13/5817.short

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4760112/ Cardiac muscle

https://www.ncbi.nlm.nih.gov/pubmed/23899560 Striated muscle

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4192353/ Adipose tissue