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My biology textbook includes a point that lysosomes stimulates cell division without further elaborating. But studying it, I felt eerie about this function of lysosome. Then, I checked on the internet; found nothing relating cell division to lysosomes.

Maybe, autophagy of lysosomes can play a role in this regard. Killing cells and thus 'stimulating' cell division. But this reasoning doesn't seem plausible as autophagy doesn't occur without extreme conditions.

Nothing else is coming into my mind.

So, is this point included in my book wrong or right?

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    $\begingroup$ You're incorrect about autophagy - it occurs all the time. $\endgroup$ – MattDMo Jan 4 '17 at 21:41
  • $\begingroup$ Really? I thought it occurred when there is a shortage of food or other extreme conditions. $\endgroup$ – Mockingbird Jan 5 '17 at 0:11
  • $\begingroup$ Nope. Read Wikipedia for an intro, then go to PubMed for recent review articles. $\endgroup$ – MattDMo Jan 5 '17 at 0:12
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It is actually not completely correct to include it as a fact in textbooks. The main cause of it is that there is not much research on this topic. See this article for reference. According to Allison and Mallucci (1964), during cell division, lysosomes either released an unspecified activator or some hydrolase that inactivated a repressor. Apart from this, Allison and Paton (1965) showed that treatment of human embryonic lung cells in tissue culture with photosensitizing agents allowed high frequency of chromosome breaks on irradiating the cells with light from a high intensity tungsten source. They claimed that these effects were observed only at lysosomal sites, from which they concluded that a cytoplasmic event was giving rise to structural alteration in chromosomes. This event was suggested to be release of deoxyribonuclease from the lysosomes. However, Chevremont et al, 1959 showed different results through their experiments. They grew mammalian cells in tissue culture in the presence of acid deoxyribonuclease. This treatment inhibited cell division, but allowed DNA synthesis to proceed and did not appear to alter the nuclear DNA. Hence, the contribution of lysosomes in cell division is not yet completely established and still comes under debate.

So, it should not be considered a total false, but is also not reliable enough to be printed in textbooks. Overall, we don't yet know whether lysosomes do play a role or not.

References:

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  • $\begingroup$ Well, how can acidic deoxyribonuclease inhibits cell division without inhibiting dna synthesis? $\endgroup$ – Mockingbird Jan 5 '17 at 0:25
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    $\begingroup$ I ain't sure, but nuclease would simply cut the DNA due to which cell would prioritize DNA repair instead of cell division. Thus it could inhibit cell division by creating breaks in DNA continuously. $\endgroup$ – another 'Homo sapien' Jan 5 '17 at 4:38
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Well. I can show how they could be seen to be linked.

Taking cell division to mean the full process of mitosis – producing identical copies of a particular cell.

The mitotic apparatus would be present to aid in the separation of chromosomes during metaphase. One protein associated with the mitotic apparatus is "Nuclear mitotic apparatus protein 1"

In order to carefully control and regulate the amount of this protein present, the lysosome is able to degrade the protein.

So the lysosome is responsible for regulating a key protein associated with and vital for mitosis. `

Jeffrey Van Ness, David E. Pettijohn, A. Klug, Specific attachment of nuclear-mitotic apparatus protein to metaphase chromosomes and mitotic spindle poles: Possible function in nuclear reassembly, Journal of Molecular Biology, Volume 171, Issue 2, 5 December 1983, Pages 175-205, ISSN 0022-2836, http://doi.org/10.1016/S0022-2836(83)80352-0.

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    $\begingroup$ Please add some references to your answer. Has this process ever been reported in vivo or in vitro? $\endgroup$ – another 'Homo sapien' Apr 18 '17 at 10:00
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    $\begingroup$ Would you elaborate "In order to carefully control and regulate the amount of this protein present, the lysosome is able to degrade the protein."? $\endgroup$ – Mockingbird Apr 18 '17 at 10:05
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    $\begingroup$ From what I have read and what is indicated however a mechanism is not provided. $\endgroup$ – user20453 Apr 18 '17 at 10:10
  • $\begingroup$ Would you please elaborate the passage I pointed out? $\endgroup$ – Mockingbird Apr 18 '17 at 23:24
  • $\begingroup$ @Mockingbird The article which I read merely mentioned this in passing. It said that the protein was degraded by lysosomes. This as deep as it went into explaining the mechanism. $\endgroup$ – user20453 Apr 18 '17 at 23:27

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