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Banking occupies one of the most important positions in the modern economic world. It is necessary for trade and industry. Hence it is one of the great agencies of commerce. Modern banking services presence is very helpful to the economic activity and industrial progress of the country. The banking industry is on a major technological up gradation drive after having successfully introduced international standards in their operating norms. It is commonly perceived that technology is important to enhance the quality of customer service and to make it customer friendly. Banking industry is fast growing with the use of technology in the form of ATMs, on line banking, Telephone banking, Mobile banking etc., plastic card is one of the banking products that cater to the needs of retail segment has seen its number grow in geometric progression in recent years. Today, the concept of core banking has made Any Where and any time banking a reality. Along with technology, banking services have also evolved and the delivery of various banking products are carried out through the medium of high technology at a fraction of the cost to the customer. This paper focus on how the technological services in banking sector luring the sustainable development. Aijaz Rashid | Shazia Ahad "Cell Cycle Dependent Regulation of Microtubule Dynamics by Microtubules Associated Proteins (MAPs) and its Misregulation causes Aneuploidy" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-1 | Issue-5 , August 2017, URL: https://www.ijtsrd.com/papers/ijtsrd2409.pdf Paper URL: http://www.ijtsrd.com/management/accounting-and-finance/2409/cell-cycle-dependent-regulation-of-microtubule-dynamics-by-microtubules-associated-proteins-maps-and-its--misregulation-causes-aneuploidy/aijaz-rashid
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@ IJTSRD | Available Online @ www.ijtsrd.com
ISSN No: 2456
InternationalResearch
Cell Cycle Dependent Regulation of Microtubule Dynamics bMicrotubules Associated Proteins (MAPs) and i
Misregulation
Aijaz Rashid* Postdoctoral Research Fellow
National Institutes of Health, NIH,*Corresponding author: [email protected]
ABSTRACT Microtubules are intrinsic dynamic polymers but programmed regulation of microtubule dynamics through different phases of cell cycle is modulated by numerous proteins known as microtubules associated proteins (MAPs) and mitotic kinases. Proper attachment of microtubules with kinetochore and adequate tension generation leads to chromosomal congression at metaphase plate, that is followed by movement of sister chromatids towards opposite poles of cells. Impairment, in this process activates spindle assembly checkpoint proteins that hamper cell cycle progression and thus maintains genetic stability. Thus, regulation of microtubule dynamics is important in normal cell cycle progression and to prevent aneuploidy.
Although microtubules are intrinsic dynamic polymers but programmed regulation of microtubule dynamics through different phases of cell cycle is modulated by numerous proteins known as microtubules associated proteins (MAPs) and mitotic kinases[1-3]. Various MAPs present inside the cell maintain balance between polymeric and soluble pool of tubulin and are also responsible for reorientatmicrotubule cytoskeleton. Microtubules perform indispensable role in mitosis. During mitosis microtubules attain high dynamic state, 20increase in microtubule dynamics is observed during mitosis. The nucleation rate of microtubules from centrosomes during mitosis shows 7-fold
@ IJTSRD | Available Online @ www.ijtsrd.com | Volume – 1 | Issue – 5 | July - Aug
ISSN No: 2456 - 6470 | www.ijtsrd.com | Volume
International Journal of Trend in Scientific Research and Development (IJTSRD)
International Open Access Journal
Cycle Dependent Regulation of Microtubule Dynamics btubules Associated Proteins (MAPs) and i
egulation causes Aneuploidy
esearch Fellow, NIH, USA
Shazia AhadIndian Institute of Technology(
Maharastra, India
Microtubules are intrinsic dynamic polymers but programmed regulation of microtubule dynamics through different phases of cell cycle is modulated by numerous proteins known as microtubules associated
(MAPs) and mitotic kinases. Proper attachment of microtubules with kinetochore and adequate tension generation leads to chromosomal congression at metaphase plate, that is followed by movement of sister chromatids towards opposite poles
nt, in this process activates spindle assembly checkpoint proteins that hamper cell cycle progression and thus maintains genetic stability. Thus, regulation of microtubule dynamics is important in normal cell cycle progression and to prevent
lthough microtubules are intrinsic dynamic polymers but programmed regulation of microtubule dynamics through different phases of cell cycle is modulated by numerous proteins known as microtubules associated proteins (MAPs) and mitotic
. Various MAPs present inside the cell maintain balance between polymeric and soluble pool of tubulin and are also responsible for reorientation of microtubule cytoskeleton. Microtubules perform indispensable role in mitosis. During mitosis microtubules attain high dynamic state, 20-100 folds increase in microtubule dynamics is observed during mitosis. The nucleation rate of microtubules from
fold
enhancement, compared to the interphase microtubules[4, 5]. There is drastic reduction inlife of polymerized tubulin from 10 minute in interphase cell to merely 10–30 s in mitotic cell
The functional significance of enhanced dynamics after breakdown of nuclear envelope (prophase and prometaphase) is strategic kinetochore capture by highly dynamic microtubules. Highly dynamic microtubules display extended search for kinetochore and get hold of it by increasing in length followed by instantaneous shortening to bring it to metaphase plate[7].
This stochastic search-and-capture process displayed by microtubules emanating from one spindle pole capture kinetochore and a similar process allows other kinetochore of the same chromosomes to be captured by microtubules from other spindle pole, resulting in amphitelic kinetochore-microtubule attachments (51).This process involves proper tension generation and chromosomal congression at so called metaphase plate[8], followed by movement of sister chromotids towards opposite poles of cell. The poleward movement of chromatids is thought to be driven by shortening of kinetochore-Some motor proteins also contribute in poleward movement of chromatids as well as in chromosomal congression process [9]. The segregation of chromosomes is followed by dephase of mitosis (telophase), thus two identical nuclei are formed. Finally cytokinesis takes place where in
Aug 2017 Page: 1269
6470 | www.ijtsrd.com | Volume - 1 | Issue – 5
Scientific (IJTSRD)
International Open Access Journal
Cycle Dependent Regulation of Microtubule Dynamics by tubules Associated Proteins (MAPs) and its
Shazia Ahad Technology(IIT) Bombay,
Maharastra, India
enhancement, compared to the interphase . There is drastic reduction in half-
life of polymerized tubulin from 10 minute in 30 s in mitotic cell[5, 6].
The functional significance of enhanced dynamics after breakdown of nuclear envelope (prophase and prometaphase) is strategic kinetochore capture by highly dynamic microtubules. Highly dynamic
ended search for kinetochore and get hold of it by increasing in length followed by instantaneous shortening to bring it to metaphase
capture process displayed by microtubules emanating from one spindle pole
imilar process allows other kinetochore of the same chromosomes to be captured by microtubules from other spindle pole, resulting in
microtubule attachments (51).This process involves proper tension generation
ssion at so called metaphase , followed by movement of sister chromotids
towards opposite poles of cell. The poleward movement of chromatids is thought to be driven by
-attached microtubules. Some motor proteins also contribute in poleward movement of chromatids as well as in chromosomal
. The segregation of chromosomes is followed by de-condensation in last
s (telophase), thus two identical nuclei are formed. Finally cytokinesis takes place where in
International Journal of Trend in Scientific Research and Development (IJTSRD) ISSN: 2456-6470
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cytoplasm is divided by the contractile action of actin-myosin ring structures originating at the central
position of cell[10].
Figure 1: Microtubule dynamics and kinetochore capture: After the breakdown of nuclear envelope, microtubules emanating from centrosome called as kinetochore microtubules get hold of kinetochores of chromosomes and align chromosomes at medial position of cell called as metaphasic plate. Microtubule dynamics plays a vital role in kinetochore capture process. Panel A represents a cell in prometaphase and panel B represents cell in metaphase after chromosomes are aligned at metaphase plate. During the progression of cell cycle, attachment of the microtubules to the chromosomes at kinetochores and their metaphasic alignment is of utmost importance because the mitotic cell has to ensure that chromosomes are rightly aligned in metaphase before the anaphase is started to ensure proper segregation of chromosomes to the newly formed daughter cells [11]. However, the failure in this process can lead to aberrant chromosome segregation with unaligned chromosomes which could be a cause for chromosomal instability and aneuploidy[12, 13]. To prevent aneuploidy, a stringent signal transduction pathway operates called as “the spindle assembly checkpoint”. It is a cell cycle surveillance mechanism
which postpones the onset of anaphase till all kinetochores are firmly adhered to spindle microtubules and proper tension is achieved[12]. The spindle checkpoint signaling mechanism comprises of several highly conserved proteins like Mad1, Mad2, Mad3/BubR1, Bub1, Bub3 and Mps1 [13]. During nuclear envelope breakdown kinetochore attachment process starts and spindle checkpoint proteins are activated and recruited to unattached kinetochores and kinetochores devoid of proper tension, resulting in the inhibition of anaphase-promoting-complex/cyclosome (APC/C). An activated spindle checkpoint prevents the beginning of anaphase through inhibition of protein proteolysis and hence prevention of chromatid separation[11, 13]. However, compromised spindle checkpoint mechanism may result in faulty separation of sister chromatids even in the presence of misaligned chromosomes that could be a cause for chromosomal instability (CIN) and hence result in gain or loss of chromosomes called as aneuploidy, a striking feature in human cancer[14]. Significantly, many tumors are known with weakened spindle checkpoint function, thus lack of sustenance of signal for repair of errors[15, 16]. Hence, an impaired spindle checkpoint may directly lead to chromosomal instability and tumorigenesis in human cancer[15].
A
B
International Journal of Trend in Scientific Research and Development (IJTSRD) ISSN: 2456
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Figure 2: Mitotic progression: (A) On each kinetochore, when microtubules are adhered and proper tension is generated, the checkpoint proteins are satisfied and released. Then anaphase promoting complex (APC/C) promotes ubquitination of cyclin B and its degradation by 26S proteasome thus providing the biochemical signal for cells to proceed towards anaphase. (B) On the other hand, unattached kinetochore and imbalanced kinetochore tension leads to recruitment of SAC proteins (Mad2, BubR1) to Kinetochore. SAC proteins sequester Cdc20 a cofactor of APC/C, thus inhibiting proteosomal degradation of Cyclin B and Securin. Cyclin B is a protein which regulates early phase of mitosis and securin is inhibitor of separase. Thus, preventproteosomal degradation of Cyclin B and Securin leads to mitotic block.
A
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(A) On each kinetochore, when microtubules are adhered and proper tension is generated, the checkpoint proteins are satisfied and released. Then anaphase promoting
itination of cyclin B and its degradation by 26S proteasome thus providing the biochemical signal for cells to proceed towards anaphase. (B) On the other hand, unattached kinetochore and imbalanced kinetochore tension leads
Mad2, BubR1) to Kinetochore. SAC proteins sequester Cdc20 a cofactor of APC/C, thus inhibiting proteosomal degradation of Cyclin B and Securin. Cyclin B is a protein which regulates early phase of mitosis and securin is inhibitor of separase. Thus, prevention of proteosomal degradation of Cyclin B and Securin
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