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General Knowledge about Glucokinase[edit]

This article is well written and is somewhat easy to understand. The pictures and diagrams help understand the material much better. One thing you should consider when editing this page is trying to dumb down the material. If someone needs information on Glucokinase, and they are not in Biochemistry or a science class, they would not be able to understand this material. Kendall AdcockKadcock12 (talk) 14:38, 6 April 2017 (UTC)

equation correction[edit]

For expl see User talk:Jag123 alteripse 02:36, 27 Jan 2005 (UTC)

Section titles[edit]

Firstly may I compliment Alteripse on his phenomenal work on this page! My only complaint is the length of the section titles. I would not try to condense all information in a paragraph in the section title. Section 9.3 is called Function and regulation of GK in the brain: glucose sensing in the hypothalamus. This is a subsection of 9, Function and regulation of GK in the pancreas and other neuroendocrine tissue. I would propose to name section 9 "Function and regulation", and 9.3 to "Brain". No information is lost this way. JFW | T@lk 20:42, 3 Feb 2005 (UTC)

Your appreciation is appreciated; so is your suggestion. I am thinking about the headings. I did them first without the explanatory phrase and thought it looked too boringly repetitive ("function & regulat in this, function & regulat in that, etc). I also thought that the amount of detail might be daunting, so I added the explanatory phrases as the main message of each section in hope that it would provide the reader a quick overview but still be "graspable" at a glance. Those reasons don't persuade you? I wonder if we can get another opinion? I admit I tend to be hard to persuade to change my writing even while quick to alter someone else's. What can I say? It's probably the quirk that keeps me writing here. alteripse 21:46, 3 Feb 2005 (UTC)

Here's my $0.02: I like the explanatory phrases (ie: "suppression of glucagon?") because it sounds interesting, but I find having "Function and regulation of GK" in every single header is repetitive. What about something like "Function and regulation of GK" as a main header, and "Alpha cells: Suppression of glucagon?" or "Brain: Glucose sensing in the hypothalamus" etc ? --jag123 23:09, 3 Feb 2005 (UTC)

Thanks. I like the suggestion. See if you both think the new titles are improved. alteripse 23:22, 3 Feb 2005 (UTC)

This is much better. I do like Jag123's suggestion, as long as the section titles remain within the 35-30 character range. Any longer is actually more confusing (see any general encyclopedia). JFW | T@lk 11:25, 4 Feb 2005 (UTC)

I find them a bit much myself - I've never seen an FA with section titles like that. It's very striking when you see the TOC, and makes it harder to get an overview of the article's content quickly. There are also a very large number of sections - is there any that could be merged together, or grouped under a higher level heading? Richard001 00:45, 19 August 2007 (UTC)

on mitochondrial association[edit]

The following was added recently. It is probably useful and needs to be in the article but I wanted to clarify some things and discuss the appropriate insertion points.

Glucokinase -unlike the other three hexokinase forms- cannot associate physically to the outer surface of the external membrane of mitochondria of almost all cell types. Consequently, glucokinase plays no role in driving high-aerobic glycolysis (Warburg effect) typical of rapidly-growing malignant tumor cells.

In pancreatic beta cells, glucokinase does bind to mitochondria. This is because beta cells express an alternatively spliced version of the glucokinase gene that has an additional N-terminal sequence that permits glucokinase binding to both mitochondria and secretory granules. Glucokinase is an integral component of the insulin granules in glucose-responsive insulin secretory cells. Hepatic glucokinase lacks this N-terminal membrane binding domain.

Since GK has only been found in 4 mammalian cell types, "almost all cell types" isn't the clearest phrase. The two GK types that have been best studied have been liver and beta cell. In the liver, GK is associated with GKRP and moves from cytoplasm to nucleus. We can mention a lack of mitochondrial association in that context if you can confirm that liver is the tissue you meant by "almost all cell types". What others did you have in mind?

A second problem in the first paragraph is the phrase "consequently...". There are a lot of reasons GK does not play a role in "high-aerobic glycolysis" but they are related more to other kinetic properties explained here and to functional aspects of the relevant cell types rather than because GK doesn't associate to mitochondria. You seem to be suggesting that if GK associated with mitochondria it would have a central role in this type of metabolism. This is a distraction to the reader, who at that point in the article is no more likely to be thinking to himself, "why doesnt GK play a role in the Warburg effect" than "why doesnt GK play a role in muscle contraction."

We don't have to explain why something that isnt suggested by the context doesnt happern. The statement either needs a lot more context and explanation or it doesnt need to be here. Do other hexokinases play an important role in tumor metabolism? If so, then we can simply mention it as one of many differences between GK and other HKs. If not, then let's just leave it out.

The second paragraph is potentially interesting but again the causal conjunction "this is because" makes it unclear. Can you cite a reference that GK in beta cells is associated with both mitochondria and secretory granules? I was unaware that secretory granules were associated with mitochondria but you may be able to teach me something. Why not include this with a discussion of the association of GK with secretory granules in that section of the article?

While the neuroendocrine promoter produces a different GK molecule than the liver promoter, it is not a direct causal relationship (except for the trivial causation that proteins follow the sequence of the DNA). The more interesting aspect is whether the N-terminal chain that is different between liver GK and neuroendocrine GK is the key difference in the association capabilities. Is this trrue? If so we can say so more clearly.

I await your answers alteripse 14:27, 28 November 2005 (UTC)

Hi Alteripse. Thank you for your very insightful views. Let me answer briefly.

1) I agree that 'almost all cell types' is an unhappy clause. My main point is that glucokinase isn't associated to liver mitochondria.

2) The term consequently is indeed misleading. Although it is true that other hexokinases do play a key role in explaining high aerobic glycolysis in tumor cells [1], you're dead right in pointing out that we don't have to explain about something that isn't suggested by the context.

3) The clause "this is because" can be changed.

4) As to the reference you ask for, it is: Arden C, Harbottle A, Baltrusch S, Tiedge M and Agius L. Glucokinase is an integral component of the insulin granules in glucose-responsive insulin secretory cells and does not translocate during glucose stimulation. Diabetes 53: 2346-2352, 2004.

5) Please feel free to use your own construction to reinsert the subsection back in the article. I may chip in afterwards.

Thank you for your comments; --Tito4000 18:42, 29 November 2005 (UTC)

Thanks. I put the mention of the mitoch assoc w beta cells and non-assoc in hepatocytes in the approp sections and added your reference. alteripse 00:06, 30 November 2005 (UTC)

happyapple, please explain your edit comment[edit]

link to kilodalton, i think it would be better to use amu or g/ a chemist

What is amu? As a measure of mass, g/mol is ok with me but I would like to leave kD also because it is the mass measure many of us who are not current on new terminology are familiar with. Can both coexist? alteripse 01:25, 5 December 2005 (UTC)


Why are the names of the sections so looooooong? And why does almost every section's name have GK mentioned in it? Why is GK sometimes refered to as GK and sometimes as glucokinase, and this is throughout the whole article - there should be some consistency? What is the project that maintains this article? -- Boris 13:15, 25 January 2006 (UTC)

I am the project that wrote and maintains the article. I made the topic headings informative-- they give the main point of each section. Sorry if you dont like it, but that is a matter of taste and style. GK & glucokinase are interchangeable for variety and readability. Sorry if it doesnt match your taste. Why dont you write a comparable article on another enzyme and show me how would like it? alteripse 22:09, 25 January 2006 (UTC)

I know that they are interchangable, what i meant was that you should choose one of them and use it all the way, the other one should be just mentioned in the begining. As for article that i have written, here. Also, we need the sections to have some sort of standart names, i started a discussion at Wikipedia_talk:WikiProject_Molecular_and_Cellular_Biology (see section 3.1 Article's structure) but noone has replayed yet. -- Boris 02:55, 26 January 2006 (UTC)

I like your GLUD article. These are a couple of the best enzyme articles here. How about recognizing that before you tell me how you would prefer it? We shouldn't be criticizing each other's style differences when so many articles have sketchy or incorrect or superficial information, poorly organized. Have you noticed around here how the good articles tempt people to improve them more than the crappy ones? It makes me want to say, "go fix one of the crappy articles rather than complain about a minor style issue in a good one." Now if I haven't pissed you off entirely, do you want a contribution to the clinical implications section of your GLUD article or would you rather finish it up yourself? I know a bit about GDH hyperinsulinism, and this is a friendly offer, not a gibe or one-upmanship. alteripse 03:25, 26 January 2006 (UTC)

do you want a contribution to the clinical implications section?. Absolutely. You should not even ask, i wrote that article but i don't own it, as long as people add more, ummmm "healthy" (backed with reliable references) stuff, to it and don't try to delete the good that has already been added, i'll be cool. What project(s) are you working on? -- Boris 16:24, 26 January 2006 (UTC)