Mystery at the heart of life

_{News
December 21, 2014

Cell biology, Intelligent Design, News

1}_{Categories
Cell biology
Intelligent Design
News}

Share: Facebook; Twitter/X; LinkedIn; Flipboard; Print; Email

By Biologic Institute’s Ann Gauger, at Christianity Today’s Behemoth, the secret life of cells:

Our bodies are made up of some 100 trillion cells. We tend to think of cells as static, because that’s how they were presented to us in textbooks. In fact, the cell is like the most antic, madcap, crowded (yet fantastically efficient) city you can picture. And at its heart lies a mystery—or I should say, several mysteries—involving three special kinds of molecules: DNA, RNA, and proteins.

These molecules are assembled into long chains called polymers, and are uniquely suited for the roles they play. More importantly, life absolutely depends upon them. We have to have DNA, RNA, and protein all present and active at the same time for a living organism to live.

How they work together so optimally and efficiently is not merely amazing, but also a great enigma, a mystery that lies at the heart of life itself. More. Paywall soon after. May be worth it.

Follow UD News at Twitter!

Comments

Clearly it will be important to determine how the absence of PLP influences the dynamics of the recruitment and retention of the various components of the PCM. [...] PLP exhibits a complex network of potential self interactions and potential heterologous interactions with several other key PCM proteins, including Cnn, to fulfill this role.
The Drosophila Pericentrin-like-protein (PLP) cooperates with Cnn to maintain the integrity of the outer PCM Jennifer H. Richens, Teresa P. Barros, Eliana P. Lucas, Nina Peel, David Miguel Susano Pinto, Alan Wainman, Jordan W. Raff Biology Open 2015 4: 1052-1061; doi: 10.1242/bio.012914 http://bio.biologists.org/content/4/8/1052

Complex complexity Work in progress... stay tunedDionisio_{November 24, 2015
November
11
Nov
24
24
2015
03:20 AM
3
03
20
AM
PDT}

[...] need to determine whether other forms of chromosome mis-segregation, such as gain/loss of merotelic chromosomes, depend on centrosome age or not.
Centrosome age regulates kinetochore–microtubule stability and biases chromosome mis-segregation Ivana Gasic, Purnima Nerurkar, Patrick Meraldi DOI: http://dx.doi.org/10.7554/eLife.07909 eLife 2015;4:e07909 http://elifesciences.org/content/4/e07909

Complex complexity Work in progress... stay tunedDionisio_{November 24, 2015
November
11
Nov
24
24
2015
03:11 AM
3
03
11
AM
PDT}

The spindle assembly checkpoint (SAC) is a conserved signaling pathway that monitors faithful chromosome segregation during mitosis. [...] the underlying molecular mechanism remains unclear. [...] our results present a previously undefined mechanism by which Mps1 functions in chromosome alignment by orchestrating Ndc80C–MT interactions and highlight the importance of the precise spatiotemporal regulation of Mps1 kinase activity and kinetochore localization in accurate mitotic progression.
Dynamic localization of Mps1 kinase to kinetochores is essential for accurate spindle microtubule attachment > vol. 112 no. 33 > Zhen Dou, E4546–E4555, doi: 10.1073/pnas.1508791112

Complex complexity Work in progress... stay tunedDionisio_{November 24, 2015
November
11
Nov
24
24
2015
02:51 AM
2
02
51
AM
PDT}

The spindle assembly checkpoint (SAC) works as a surveillance mechanism to ensure accurate segregation of genetic materials during cell division. Protein kinase monopolar spindle 1 (Mps1) plays a key role in SAC, but the mechanism of Mps1 action in chromosome segregation remains elusive. Our results provide a new mechanistic insight into the spatiotemporal dynamics of Mps1 activity at the kinetochore in mitosis.
Dynamic localization of Mps1 kinase to kinetochores is essential for accurate spindle microtubule attachment Zhen Dou a , b , 1 , Xing Liu a , b , c , 1 , Wenwen Wang a , b , c , Tongge Zhu a , b , c , Xinghui Wang a , b , Leilei Xu a , b , Ariane Abrieu d , Chuanhai Fu a , b , e , Donald L. Hill f , and Xuebiao Yao a , b > vol. 112 no. 33 > Zhen Dou, E4546–E4555, doi: 10.1073/pnas.1508791112

Complex complexity Work in progress... stay tunedDionisio_{November 24, 2015
November
11
Nov
24
24
2015
02:48 AM
2
02
48
AM
PDT}

[...] to determine the mechanism by which SKA1 upregulated expression promotes PTC generation and development and whether SKA1 also has abnormal expression in other solid tumors, further study is needed.
Expression of Spindle and Kinetochore-Associated Protein 1 Is Associated with Poor Prognosis in Papillary Thyroid Carcinoma Chao Dong, Xiao-li Wang, and Bin-lin Ma Disease Markers Volume 2015 (2015), Article ID 616541, 6 pages http://dx.doi.org/10.1155/2015/616541

Complex complexity Work in progress... stay tunedDionisio_{November 24, 2015
November
11
Nov
24
24
2015
02:25 AM
2
02
25
AM
PDT}

Accurate chromosome segregation is dependent on the formation and stability of the microtubule spindle apparatus. Meiotic spindle assembly in oocytes differs from the process used during mitosis, and is regulated by unique microtubule organizing centers (MTOCs) that lack centrioles. MTOC-mediated microtubule formation is regulated, at least in part, by pericentrin in oocytes and plays a critical role in spindle formation and/or stability during the progression of meiosis. Pcnt-depleted oocytes provide a valuable model to help determine the relative contribution of these two mechanisms to meiotic spindle assembly and stability in oocytes.
Depletion of pericentrin in mouse oocytes disrupts microtubule organizing center function and meiotic spindle organization Wei Ma† and Maria M. Viveiros* DOI: 10.1002/mrd.22422 Molecular Reproduction and Development Volume 81, Issue 11, pages 1019–1029, http://onlinelibrary.wiley.com/doi/10.1002/mrd.22422/abstract

Complex complexity Work in progress... stay tunedDionisio_{November 24, 2015
November
11
Nov
24
24
2015
02:07 AM
2
02
07
AM
PDT}

MTOC plasticity may be a general mechanism to rapidly adapt MTOC function to different cellular requirements.
A three-step MTOC fragmentation mechanism facilitates bipolar spindle assembly in mouse oocytes Dean Clift & Melina Schuh Nature Communications 6, Article number: 7217 doi:10.1038/ncomms8217 http://www.nature.com/ncomms/2015/150706/ncomms8217/full/ncomms8217.html.

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
07:32 PM
7
07
32
PM
PDT}

Further analysis in C. elegans as well as studies in various other organisms are likely to continue to synergize in the future to further our knowledge of universal polarity mechanisms.
Polarity establishment, asymmetric division and segregation of fate determinants in early C. elegans embryos* Lesilee Rose and Pierre Gönczy http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.html

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
05:00 PM
5
05
00
PM
PDT}

PIE-1 is also important for activating the translation of NOS-2 in the P4 cell; although the mechanism is unknown, [...] [...] the GLP-1 receptor and the MS cell are required for the distinct lineages on the left and right sides; however the ligand in this case is not APX-1 and remains to be identified.
Polarity establishment, asymmetric division and segregation of fate determinants in early C. elegans embryos* Lesilee Rose and Pierre Gönczy http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.html

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
04:56 PM
4
04
56
PM
PDT}

[...] whether MEX-5 and MEX-1 are involved in the degradation or posterior enrichment of SKN-1 remains to be determined. [...] the details regarding the mechanisms underlying some of these interactions remain to be elucidated. It remains to be determined how early polarity cues localize Wnt and MES-1 activity.
Polarity establishment, asymmetric division and segregation of fate determinants in early C. elegans embryos* Lesilee Rose and Pierre Gönczy http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.html

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
04:53 PM
4
04
53
PM
PDT}

[...] asymmetric dynactin accumulation may provide a useful tool to further dissect how Wnt signaling regulates spindle movements. [...] it will be of interest to detemine if the removal of WRM-1 is necessary for dynactin accumulation in EMS. [...] the anterior PARs act not only to orient spindles onto a specific axis, but to prevent cell shape from affecting division pattern, through an unknown mechanism. [...] it remains to be determined how the cytoplasmic PAR-1 gradient is produced [...]
Polarity establishment, asymmetric division and segregation of fate determinants in early C. elegans embryos* Lesilee Rose and Pierre Gönczy http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.html

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
04:49 PM
4
04
49
PM
PDT}

Embryos with impaired G?? function have abnormal centrosome positioning and retarded rotation in P1, but it remains to be determined if these defects are due to excess G?, as for P0, or whether G?? plays a separate role in P1 spindle positioning. There are several other genes required for P1 nuclear rotation, but their precise roles remain to be determined.
Polarity establishment, asymmetric division and segregation of fate determinants in early C. elegans embryos* Lesilee Rose and Pierre Gönczy http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.html

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
04:44 PM
4
04
44
PM
PDT}

[...] how the presence of PPK-1 on the posterior would result in increased cortical GPR-1/2 and LIN-5 remains to be clarified. It will be interesting to identify the nature of the responsible kinase and the identity of the substrate that it phosphorylates. [...] whether the role of NMY-2 is mediated entirely through LET-99 and its impact on GPR-1/2 distribution or instead by a separate means remains to be determined.
Polarity establishment, asymmetric division and segregation of fate determinants in early C. elegans embryos* Lesilee Rose and Pierre Gönczy http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.html

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
04:40 PM
4
04
40
PM
PDT}

The wealth of information regarding the relationships between anterior and posterior polarity components, as well as knowledge about their dynamics and that of the underlying actomyosin network, have fueled mathematical modeling of how AP polarity is achieved in one-cell C. elegans embryos. [...] mutual interactions between anterior and posterior PAR proteins have lent themselves to mathematical modeling, and future work in this direction is anticipated to unveil further tenets of the underlying mechanisms of AP polarity.
Polarity establishment, asymmetric division and segregation of fate determinants in early C. elegans embryos* Lesilee Rose and Pierre Gönczy http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.html

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
04:35 PM
4
04
35
PM
PDT}

What are the properties of the actomyosin network during the anteriorly-directed flow of cortical material? [...] anterior-restricted anisotropy in cortical contractility can be instrumental in polarity establishment. PAR proteins constitute a dynamic ensemble, whose kinetics must be taken into consideration when reflecting upon the mechanisms of polarity establishment. [...] whether trafficking events are instructive for directing AP polarity or merely elements that contribute in a more passive manner through their general requirement for cell physiology remains to be clarified.
Polarity establishment, asymmetric division and segregation of fate determinants in early C. elegans embryos* Lesilee Rose and Pierre Gönczy http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.html

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
04:29 PM
4
04
29
PM
PDT}

Polarity establishment, asymmetric division, and acquisition of cell fates are critical steps during early development. During development, cells acquire distinct fates, and one prominent mechanism by which this is achieved is asymmetric division. What are the mechanisms leading to the local cessation of cortical contractions following symmetry breaking? [...] the mechanisms by which CYK-4 may contribute to polarity establishment remain to be further clarified [...]
Polarity establishment, asymmetric division and segregation of fate determinants in early C. elegans embryos* Lesilee Rose and Pierre Gönczy http://www.wormbook.org/chapters/www_asymcelldiv.2/asymcelldiv.2.html

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
04:22 PM
4
04
22
PM
PDT}

Cell polarity is characterized by the asymmetric distribution of factors at the cell cortex and in the cytoplasm. Although mechanisms that establish cortical asymmetries have been characterized, less is known about how persistent cytoplasmic asymmetries are generated. [...] local modulation of protein mobility provides a robust and rapid mechanism by which cytoplasmic concentration gradients can be established at cellular length scales.
Coupling between cytoplasmic concentration gradients through local control of protein mobility in the Caenorhabditis elegans zygote Youjun Wu, Huaiying Zhang, and Erik E. Griffin doi: 10.1091/mbc.E15-05-0302 http://www.molbiolcell.org/content/26/17/2963.full

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
01:04 PM
1
01
04
PM
PDT}

Book chapters and reviews that were previously focused on specific hormones now address aspects of programmed and plastic development and their by genetics, epigenetics, protein modification, second messengers, and hormones.
Hormone crosstalk in plants Angus Murphy J. Exp. Bot. (2015) 66 (16): 4853-4854. doi: 10.1093/jxb/erv339 http://jxb.oxfordjournals.org/content/66/16/4853.full

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
06:18 AM
6
06
18
AM
PDT}

This transition has accompanied a profound shift in the way that plant physiology and development are taught in the classroom, with undergraduate and graduate courses increasingly combining physiology and development as inseparable components of growth.
Hormone crosstalk in plants Angus Murphy J. Exp. Bot. (2015) 66 (16): 4853-4854. doi: 10.1093/jxb/erv339 http://jxb.oxfordjournals.org/content/66/16/4853.full

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
06:15 AM
6
06
15
AM
PDT}

The classification of hormones into developmental or environmental response categories has been replaced by mapping of hormonal signalling into transcriptional and post-transcriptional response networks.
Hormone crosstalk in plants Angus Murphy J. Exp. Bot. (2015) 66 (16): 4853-4854. doi: 10.1093/jxb/erv339 http://jxb.oxfordjournals.org/content/66/16/4853.full

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
06:12 AM
6
06
12
AM
PDT}

Over time, simple models of hormone antagonism (gibberellic acid vs. abscisic acid, auxin vs. cytokinin) have been displaced by the concept of complex hormonal crosstalk.
Hormone crosstalk in plants Angus Murphy J. Exp. Bot. (2015) 66 (16): 4853-4854. doi: 10.1093/jxb/erv339 http://jxb.oxfordjournals.org/content/66/16/4853.full

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
06:07 AM
6
06
07
AM
PDT}

Over the past two decades, new hormones have been identified, tissue and organ-specific hormone functions have been determined, methods have been developed to measure and visualize hormones in situ, receptor mechanisms have been conclusively identified or discounted, hormone transport processes have been largely elucidated, and the cellular processes downstream of hormone signalling have been painstakingly dissected.
Hormone crosstalk in plants Angus Murphy J. Exp. Bot. (2015) 66 (16): 4853-4854. doi: 10.1093/jxb/erv339 http://jxb.oxfordjournals.org/content/66/16/4853.full

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
06:00 AM
6
06
00
AM
PDT}

Auxin (indole acetic acid) is a multifunctional phytohormone controlling various developmental patterns, morphogenetic processes, and growth behaviours in plants. The transcription-based pathway activated by the nuclear TRANSPORT INHIBITOR RESISTANT 1/auxin-related F-box auxin receptors is well established, but the long-sought molecular mechanisms of non-transcriptional auxin signalling remained enigmatic until very recently. Along with the establishment of the Arabidopsis leaf epidermal pavement cell (PC) as an exciting and amenable model system in the past decade, we began to gain insight into non-transcriptional auxin signalling. The puzzle-piece shape of PCs forms from intercalated or interdigitated cell growth, requiring local intra- and inter-cellular coordination of lobe and indent formation. Precise coordination of this interdigitated pattern requires auxin and an extracellular auxin sensing system that activates plasma membrane-associated Rho GTPases from plants and subsequent downstream events regulating cytoskeletal reorganization and PIN polarization. Apart from auxin, mechanical stress and cytokinin have been shown to affect PC interdigitation, possibly by interacting with auxin signals. This review focuses upon signalling mechanisms for cell polarity formation in PCs, with an emphasis on non-transcriptional auxin signalling in polarized cell expansion and pattern formation and how different auxin pathways interplay with each other and with other signals.
Pavement cells: a model system for non-transcriptional auxin signalling and crosstalks 1. Jisheng Chen, 2. Fei Wang, 3. Shiqin Zheng, 4. Tongda Xu and 5. Zhenbiao Yang J. Exp. Bot. (2015) 66 (16): 4957-4970. doi: 10.1093/jxb/erv266 http://jxb.oxfordjournals.org/content/66/16/4957.abstract?cited-by=yes&legid=jexbot;66/16/4957

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
05:35 AM
5
05
35
AM
PDT}

Deciphering the mechanism of BAM repression by CLV1 signaling should reveal novel downstream aspects of this key regulatory pathway in stem cell regulation. How dominant-negative CLV1 proteins act to dampen BAM function is unclear.
Plant stem cell maintenance by transcriptional cross-regulation of related receptor kinases Zachary L. Nimchuk, Yun Zhou, Paul T. Tarr, Brenda A. Peterson, Elliot M. Meyerowitz Development 2015 142: 1043-1049; doi: 10.1242/dev.119677 http://dev.biologists.org/content/142/6/1043

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
03:58 AM
3
03
58
AM
PDT}

Mystery in genetics: PUB4 gives a clue to the complex mechanism of CLV signaling pathway...
@1220 - interesting title for a research paper on plant biology, in the middle of the second decade of the 21st century, isn't it? Complex complexity. Work in progress… stay tuned.Dionisio_{November 23, 2015
November
11
Nov
23
23
2015
03:35 AM
3
03
35
AM
PDT}

Live imaging of F-actin dynamics in in vivo germinating pollen will be necessary to address the question whether F-actin rings have a transient physiological function in germinating pollen.
F-actin forms mobile and unwinding ring-shaped structures in germinating Arabidopsis pollen expressing Lifeact DOI:10.1080/15592324.2015.1075684 Frank Voglera & Stefanie Spruncka* http://www.tandfonline.com/doi/full/10.1080/15592324.2015.1075684

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
03:20 AM
3
03
20
AM
PDT}

[...] little is known about the physiological mechanisms and routes of signal movement. […] the mechanism of signal dissemination within distant leaves is unknown. Whether plasmodesmata are actively dilated to facilitate SAR signal movement is currently unknown and should be addressed in future investigations. […] investigating the relative contributions of apoplastic and symplastic phloem loading will provide deeper insight into the regulation of SAR and long-distance transport processes in general.
Mind the gap: Signal movement through plasmodesmata is critical for the manifestation of SAR DOI:10.1080/15592324.2015.1075683 Philip Carellaa, Daniel C Wilsona & Robin K Camerona* http://www.tandfonline.com/doi/full/10.1080/15592324.2015.1075683

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
03:05 AM
3
03
05
AM
PDT}

Systemic acquired resistance (SAR) is a plant defense response in which an initial localized infection affords enhanced pathogen resistance to distant, uninfected leaves. SAR requires efficient long-distance signaling between the infected leaf, where SAR signals are generated, and the distant uninfected leaves that receive them.
Mind the gap: Signal movement through plasmodesmata is critical for the manifestation of SAR DOI:10.1080/15592324.2015.1075683 Philip Carellaa, Daniel C Wilsona & Robin K Camerona* http://www.tandfonline.com/doi/full/10.1080/15592324.2015.1075683

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
02:48 AM
2
02
48
AM
PDT}

Further analysis of the effect of GA-GID1 binding for the interaction between DELLAs and other interaction proteins provides new insight for the mechanism of non-proteolytic regulation of DELLA.
Binding of GID1 to DELLAs promotes dissociation of GAF1 from DELLA in GA dependent manner DOI:10.1080/15592324.2015.1052923 Jutarou Fukazawaab*, Takeshi Itoa, Yuji Kamiyab, Shinjiro Yamaguchib & Yohsuke Takahashia http://www.tandfonline.com/doi/full/10.1080/15592324.2015.1052923

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
02:40 AM
2
02
40
AM
PDT}

It's not known if BABA affects PRR levels or trafficking to the plasma membrane as SA signaling does, [...] [...] we speculate that such regulation may explain some effects of BABA. Additionally, it seems likely that LecRK-VI.2 or other receptor-like kinases also might be involved in SA signaling, something that will be interesting to investigate in the future.
Linking pattern recognition and salicylic acid responses in Arabidopsis through ACCELERATED CELL DEATH6 and receptors DOI:10.1080/15592324.2015.1010912 Chika Tatedaa, Zhongqin Zhanga & Jean T Greenberga* http://www.tandfonline.com/doi/full/10.1080/15592324.2015.1010912

Complex complexity Work in progress... stay tunedDionisio_{November 23, 2015
November
11
Nov
23
23
2015
02:29 AM
2
02
29
AM
PDT}

Prev 1 … 74 75 76 77 78 … 117 Next

You must be logged in to post a comment.

Leave a Reply