Placas de sinalização de divisão celular para cromossomos ao longo da "rodovia" de microtúbulos: mero acaso, fortuita necessidade ou design inteligente?

segunda-feira, maio 25, 2015

Published Online April 23 2015

Science 15 May 2015: 

Vol. 348 no. 6236 pp. 799-803 

DOI: 10.1126/science.aaa5175

REPORT

Microtubule detyrosination guides chromosomes during mitosis

Marin Barisic1,2, Ricardo Silva e Sousa3,*, Suvranta K. Tripathy3,*, Maria M. Magiera4,5,6,*, Anatoly V. Zaytsev3,7,8, Ana L. Pereira1,2, Carsten Janke4,5,6, Ekaterina L. Grishchuk3,†,‡, Helder Maiato1,2,9,†,‡

- Author Affiliations

1Chromosome Instability and Dynamics Laboratory, Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal.

2Instituto de Investigação e Inovação em Saúde–i3S, Universidade do Porto, Portugal.

3Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.

4Institut Curie, 91405 Orsay, France.

5Paris Sciences et Lettres (PSL) Research University, 75005 Paris, France.

6Centre National de la Recherche Scientifique UMR 3348, 91405 Orsay, France.

7Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences (RAS), Moscow, Russia.

8Federal Research and Clinical Centre of Pediatric Hematology, Oncology and Immunology, Moscow, Russia.

9Cell Division Unit, Department of Experimental Biology, Faculdade de Medicina, Universidade do Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal.

↵†Corresponding author. E-mail: maiato@ibmc.up.pt (H.M.); gekate@mail.med.upenn.edu (E.L.G.)

↵* These authors contributed equally to this work.

↵‡ These authors contributed equally to this work.

Source/Fonte: Ekaterina Grishchuk, PhD, Perelman School of Medicine, University of Pennsylvania  

ABSTRACT EDITOR'S SUMMARY

Before chromosomes segregate into daughter cells, they align at the mitotic spindle equator, a process known as chromosome congression. Centromere-associated protein E (CENP-E)/Kinesin-7 is a microtubule plus-end–directed kinetochore motor required for congression of pole-proximal chromosomes. Because the plus-ends of many astral microtubules in the spindle point to the cell cortex, it remains unknown how CENP-E guides pole-proximal chromosomes specifically toward the equator. We found that congression of pole-proximal chromosomes depended on specific posttranslational detyrosination of spindle microtubules that point to the equator. In vitro reconstitution experiments demonstrated that CENP-E–dependent transport was strongly enhanced on detyrosinated microtubules. Blocking tubulin tyrosination in cells caused ubiquitous detyrosination of spindle microtubules, and CENP-E transported chromosomes away from spindle poles in random directions. Thus, CENP-E–driven chromosome congression is guided by microtubule detyrosination.

+++++

Professores, pesquisadores e alunos de universidades públicas e privadas com acesso ao site CAPES/Periódicos podem acessar gratuitamente a Science e mais 37.000 publicações científicas.

+++++

PERGUNTA INDISCRETA DESTE BLOGGER:

Mas Darwin não tinha eliminado de vez a teleologia da biologia em 1859??? Como a biologia do século 21, uma ciência de informação, ainda paga tributos e loas a uma hipótese de transmutação que não se corrobora no contexto de justificação teórica? 

Darwinismo: Ciência ou Ideologia???