Comprehensive Analysis: Gwl, CDK1, and the Mitotic Process in Cells

This report delves into the critical role of Greatwall kinase (Gwl) and Cyclin-Dependent Kinase 1 (CDK1) in the process of mitosis, the cell division process. It examines how Gwl, through its kinase activity, influences the inactivation of PP2A-B55 and promotes phosphorylation, key events in regulating the cell cycle. The study highlights the importance of protein coordination and the complex network of kinases and phosphatases involved. The report further discusses the impact of Gwl on nuclear localization, the function of Polo and the significance of endosulfines in the mitotic process. Various research findings, including those from Glover, Maiato, Orellana-Garcia, and others, are integrated to present a detailed model of Gwl's function, including its cytoplasmic and nuclear substrates, and its impact on the timing of events such as nuclear envelope breakdown. It also discusses the interplay between Gwl, CDK1, and other proteins like PP2A-Cdc55 and Polo, underscoring their roles in ensuring proper mitotic progression and the consequences of their dysregulation. The report concludes with a model illustrating the impact of Gwl at different stages of mitosis, emphasizing the need for a comprehensive understanding of these interactions to fully grasp the regulation of cell division.

POLO & CDK1
Examining the Role of Greatwall in
Mitosis
Recent studies have shown that critical protein coordination is essential in cell division and these
fundamental quantities include phosphatases and kinase. In fact, Greatwall kinase or also known as Gwl
plays an essential role in the mitotic process by inactivating PP2A-B55 at the entry point while at the same
time promoting phosphorylation. However, the understanding of the primary function of Greawall kinase
in the mitotic process is still inadequate.
Author’ Name:
The cell cycle is not only
triggered and driven by the
molecular events but also
regulated through the use of
kinase complex network.
Additionally, the present
phosphatases also accelerate cell
cycle activities in a cyclical
order. Moreover, cyclin-
dependent kinase one existing in
the complex form along with
cyclin B helps in the mitosis
process (Maiato., 2014 p.134). The
quality promotes nuclear
wrapper breakdown, spindle
assembly as well as chromosome
condensation. According to
Orellana-Garcia et al. (2016, p
95), cyclin B–Cdk1 forms the
basis of many regulatory and
effector proteins which targets
mitosis process. The
corresponding components of
cyclin B–Cdk1 also known as
phosphorylation have to be
reversed as a mechanism of
allowing for the mitotic exit once
the process comes to a
completion. The study also
confirms that protein
phosphatase 2A has to employed
to necessitate dephosphorylation
process, however; the substrate
must be admitted in its complex
form. Moreover, it is essential to
conduct a thorough analysis of
nuclear localization before
commencing vivo biological
function. Gwl gene enhances
growth and development of
Drosophila, however; the null
mutants tend to die immediately
the pharate adult stage begins to
take place. A Gwl activation lead

to a consequential process in the
nucleus, and this is term as
translocation in the cytoplasm,
and this depends on the
phosphorylation. Nuclear
exclusion requires Glw cyclin B–
Cdk1 phosphorylation, however;
the substance may not be useful
for the binding process in the
Polo. Also, there are two mainly
multiple phosphorylation
requirements which include Polo
as well as Cdk1, and this ensures
that Gwl relocalization
development has proper timing
and happens in a robustness
manner in accordance with the
physiological importance of the
entire process. According to
Rangone et al. (2011), Gwl plays
an essential role in the mitotic
process whenever
phosphorylating endosulfine
proteins are added to the entry of
the process. Furthermore, endos
have to be present during the cell
cycle in both cytoplasm and
nucleus, and thus, alterations in
the Gwl localization will affect
the location phosphorylated
endo. Rangone et al. (2011),
establishes that endos are defined
as small protein and it diffuse
when the substance is not bound
to other proteins through the
existing nuclear pores. However,
the study hasn't established the
localization dynamics. Endos
Phosphorylation directly inhibits
PP2A and its efficient
compartment in the cytoplasm.
Glover (2012 p.123), argued that
mitotic regulators, as well as
Gwl relative spatial coordination,
are fundamental and equally
important in line with their
functions. Furthermore, it is clear
that Gwl function losses
enhances mitotic defects and at
the same have little impact in
inhibiting the mitotic entry in the
cell types. Also, Gwl-PP2A axis
failure in the mitotic switch has
considerably affected the mitotic
events after the NEBD process.
It is also important to select and
identify key PP2A-B55
substrates factors which impact
on the mitotic process. The
substrate has to be protected
using Gwl from
dephosphorylation based on their
space, time and regulations
(Yaakov et al., 2012 p.124).
Model and its Explanation
However, cytoplasmic and
nuclear are the main and the
crucial substrates for the process.
Subsequently, prophase Gwl
retention delays NEBD from the
anaphase inception relative.
Therefore, PP2A-B55 plays an
essential role since it has to act in
the nuclear before any other
substrate such as NEBD can act
on the same. On the hand, PP2A-
Cdc55 (B55) main function is to
antagonized Scc1 cohesion Polo
phosphorylation to protect the
early chromatid mitosis

cohesion. However, similar
mechanism manifested animal
cell can also lead to impose and
demand the introduction of Gwl
nuclear exclusion. Lowering
Polo movement would lead
down to an expansion in Gwl
action in the core and thereby,
bringing about the mitotic
imperfections as well as demise
watched when Gwl action is
either expanded, or PP2A-Tws
action is diminished. Steady with
this model, maintenance of Gwl
in the core in prophase by the
change of Polo accord locales in
the focal district of Gwl prompts
long mitotic deferrals, even
within sight of endogenous Gwl.
It stays conceivable that the
hereditary collaborations
between Polo, Gwl, and PP2A-
Tws mirror various levels of
effective communications (Wang
et al., 2013 p3).

The diagram below shows a model used to the role of Gwl in the mitosis process and the impact which it
has at different stages (Pihan, 2013 p,.123).
1 A B
2
Mitosis
A 3 B B
3
Key
A. Cdk1 B. Polo
1. Interphase
2. G2 or Early Prophase
3. Late Prophase
AA
C
1
Gwl
Gwl
1
Gwl

References
1 Glover, D.M., 2012. The overlooked greatwall: a new perspective on mitotic control. Open
biology, 2(3), p.120023.
2Maiato, H. and Logarinho, E., 2014. Mitotic spindle multipolarity without centrosome
amplification. Nature cell biology, 16(5), p.386.
3Orellana-Garcia, F., Alvarez, M.A., López-Ramón, M.V., Rivera-Utrilla, J., Sanchez-Polo, M.
and Fontecha-Cámara, M.Á., 2016. Photoactivity of organic xerogels and aerogels in the
photodegradation of herbicides from waters. Applied Catalysis B: Environmental, 181, pp.94-102.
4Pihan, G.A., 2013. Centrosome dysfunction contributes to chromosome instability,
chromoanagenesis, and genome reprograming in cancer.
5Wang, P., Galan, J.A., Normandin, K., Bonneil, É., Hickson, G.R., Roux, P.P., Thibault, P. and
Archambault, V., 2013. Cell cycle regulation of Greatwall kinase nuclear localization facilitates
mitotic progression. J Cell Biol, pp.jcb-201211141.
6Yaakov, G., Thorn, K. and Morgan, D.O., 2012. Separase Biosensor Reveals that Cohesin
Cleavage Timing Depends on Phosphatase PP2A Cdc55 Regulation. Developmental cell, 23(1),
pp.124-136.