The making and breaking of microtubules ( otubule intermediates in the cell. ...)

The making and breaking of microtubules

otubule intermediates in the cell."

Richard Rodewald, a program officer and cell biologist at the National Institute of General Medical Sciences, which funded the research, noted that "these studies provide a persuasive model, in elegant atomic detail, for how binding of GTP to a specific site in tubulin leads to far-reaching structural changes that drive microtubule growth."

Building a microtubule:

Microtubules are polymers whose basic units are pairs (dimers) of similar but not identical tubulin proteins, dubbed the alpha and beta forms. During polymerization the dimers stack end to end to make a protofilament. About thirteen protofilaments are arranged side by side, extending longitudinally, to form the walls of a cylindrical microtubule.

The so-called minus end of the microtubule grows slowly and is often anchored to a cellular structure. The other end, the plus end, is a hotbed of activity. In the presence of GTP the microtubule's protofilaments acquire more tubulin dimers, and the whole microtubule extends rapidly for many millionths of a meter before suddenly switching off and shrinking again.

Nucleotides like GTP are best known as units of the nucleic acids DNA and RNA, consisting of a base (a letter in the genetic code) plus a sugar and three phosphate groups. But these molecules also regulate enzyme activity and play a crucial role in controlling microtubule growth.

When GTP binds to a particular locus on beta tubulin (the E-site or exchangeable site) polymerization occurs: tubulin dimers pile onto the protofilaments, and the microtubule grows. But through hydrolysis (the word means "water splitting"), GTP readily changes to a different nucleotide, guanosine diphosphate, or GDP. GDP-bound tubulin depolymerizes the microtubule by curling up protofilaments at its plus end and pulling it apart.

Freezing the frenzy:

Although tubulin was known to polymerize in the presence of GTP and depolymerize i
'"/>

Source:DOE/Lawrence Berkeley National Laboratory

Page: 1 2 3 4 5
Related biology news :

1. Drug That Tags Decision-making Areas Of The Brain May Aid
2. Whats really making you sick? Plant pathologists offer the science behind Sick Building Syndrome
3. Understanding biases in epidemic models important when making public health predictions
4. The making of a fat cell
5. Micro RNAs play role in egg making
6. Creationism is not science ?making the case for Darwin at UCL
7. Honeybee decision-making ability rivals any department committee
8. Ten years later, Dolly is still making headlines
9. Microbes compete with animals for food by making it stink
10. New fMRI technology making brain tumor surgery safer
11. Are scientists making progress in being able to regenerate bone tissue?

Post Your Comments:

(Date:12/16/2009)... -- BIO-key International, Inc. (OTC Bulletin Board: ... and finger-based biometric identification solutions, announced that ... Special Shareholder Meeting held today approved the ... to Interact911 Mobile Systems Inc. Of the ... and 1.2% were opposed. ,, (Logo: ...

(Date:12/16/2009)... -- CSC (NYSE: CSC ) ... Laboratory Accreditation awarded the International Organization for ... the company,s Test Lab, which is part ... Fairmont, W.Va. The Test Lab is the ... to achieve this accomplishment. ,, (Logo: ...

(Date:12/15/2009)... diseases such as Alzheimer,s and Parkinson,s, doctors can reach ... a patient. , But they come up empty-handed when ... with ataxia disabling disorders that rob people of ... are trying to change that with the help of ... of Neurological Disorders and Stroke to establish a nationwide ...

Breaking Biology News(10 mins):BIO-key(R) Shareholders Overwhelmingly Approve Sale of Law Enforcement Division 2 BIO-key(R) Shareholders Overwhelmingly Approve Sale of Law Enforcement Division 3 CSC's Identity Management and Biometric Test Lab Achieves ISO/IEC 17025 Accreditation 2 UF to lead national effort to help patients with rare brain disease 2 UF to lead national effort to help patients with rare brain disease 3 New Families and Work Institute Study Reveals Declines in the Health of American Workforce 57900 1 New Families and Work Institute Study Reveals Declines in the Health of American Workforce 57900 2 New Families and Work Institute Study Reveals Declines in the Health of American Workforce 57900 3 New Families and Work Institute Study Reveals Declines in the Health of American Workforce 57900 4 New Families and Work Institute Study Reveals Declines in the Health of American Workforce 57900 5 Sirion Therapeutics Announces FDA Approval of Zirgan 28TM 29 28Ganciclovir Ophthalmic Gel 29 0 15 25 for Herpetic Keratitis 57895 1 Sirion Therapeutics Announces FDA Approval of Zirgan 28TM 29 28Ganciclovir Ophthalmic Gel 29 0 15 25 for Herpetic Keratitis 57895 2 Sirion Therapeutics Announces FDA Approval of Zirgan 28TM 29 28Ganciclovir Ophthalmic Gel 29 0 15 25 for Herpetic Keratitis 57895 3 Sirion Therapeutics Announces FDA Approval of Zirgan 28TM 29 28Ganciclovir Ophthalmic Gel 29 0 15 25 for Herpetic Keratitis 57895 4 Advanced Analogic Technologies Introduces Lowest Power Load Switch Available for Biometric Security Devices 10022 1 Advanced Analogic Technologies Introduces Lowest Power Load Switch Available for Biometric Security Devices 10022 2 Advanced Analogic Technologies Introduces Lowest Power Load Switch Available for Biometric Security Devices 10022 3

[0] BIO-key(R) Shareholders Overwhelmingly Approve Sale of Law Enforcement Division [0] CSC's Identity Management and Biometric Test Lab Achieves ISO/IEC 17025 Accreditation [0] UF to lead national effort to help patients with rare brain disease

... as key to Komodo Dragon,s hunting strategy. , A ... Komodo Dragon bite is a combination of highly specialized ... widely accepted theory that prey die from septicemia caused ... Using sophisticated medical imaging techniques, an international team led ...

... the palm of your hand can never give accurate results. Whether ... job interview, you,re better off asking a trusted friend if your ... you need one? , Tel Aviv University researchers have come ... lets you know if malodorous bacteria are brewing in your mouth. ...

... By creating a model of the active site found ... Illinois have described a catalyst that acts like nature,s most ... a paper accepted for publication in the Journal of ... Web site. , Scientists have long been puzzled by nature,s ...

Other Biology News:A combined tooth-venom arsenal revealed as key to Komodo dragon's hunting strategy 2 Are you okay to kiss? 2 Are you okay to kiss? 3

A combined tooth-venom arsenal revealed as key to Komodo dragon's hunting strategy Are you okay to kiss?Synthetic catalyst mimics nature's 'hydrogen economy'

(Date:12/16/2009)... Trial conducted pursuant to Special Protocol Assessment ... QUEBEC CITY, Dec. 16 /PRNewswire-FirstCall/ - AEterna ... AEZ) (the "Company"), a global biopharmaceutical company ... announced the initiation, by its partner Keryx ... Phase 3 registration clinical trial for perifosine ...

(Date:12/16/2009)... has been found to be effectinve in improving yelds of probiotic ... ... BioSciences, LLC. ( www.nu-tekproducts.com ) is meeting the demand for Non-Animal ... Nutricepts, Inc. (Burnsville, Mn), is a high quality Soy Peptone. ... has been found to be especially effective in improving yields of ...

(Date:12/15/2009)... Joint BioEnergy Institute (JBEI), one of three Department of ... trusted time-stamping service to protect its valuable intellectual property. ... ... VA (PRWEB) December 15, 2009 -- Surety, LLC ... solutions , today announced that the Joint BioEnergy Institute ...

(Date:12/15/2009)... -- Reportlinker.com announces that a new market ... ,, The Future of Orphan ... Pipeline Analysis and Reimbursement ,, ... Summary ,, The author has ... Orphan Diseases Therapeutics - Market Forecasts to ...

[0] AEterna Zentaris Partner, Keryx, Initiates Phase 3 Registration Trial with Perifosine (KRX-0401) for the Treatment of Patients with Advanced Multiple Myeloma [0] Nu-Tek BioSciences, LLC. Launches Animal-Free, Non-GM Soy Peptone [0] Joint BioEnergy Institute Selects Surety's AbsoluteProof to Protect the Integrity and Legally Defend the Authenticity of its Scientific Intellectual Property [0] Reportlinker Adds The Future of Orphan Diseases Therapeutics - Market Forecasts to 2015, Pipeline Analysis and Reimbursement

... WALL, N.J., Oct. 24 BIO-key International,Inc. ... public safety,solutions and finger based biometric identification, today ... Colorado Police Department,to implement the final phase of ... of BIO-key,s Mobile Office(TM) solution. The new system,will ...

... First Nine Months of 2007 - Continued Strong Organic Growth, With Revenue Up 8.5% Like-for-Like ... months ended September 30,2007. Consolidated revenue for the first nine months, EUR millions ... 2006 (9 % change Like-for-like ... months) months) ...

... Universitys Center for Applied Nanoionics (CANi) has a new take ... capacity and battery life of consumer electronics from digital cameras ... common materials and compatible with just about anything currently on ... provided a way for this memory to be made at ...

Other Biology Technology:BIO-key(R) Awarded Contract to Deploy Incident Reporting System for Littleton, CO Police Department 2 Essilor's 2007 Third-Quarter Report 2 Essilor's 2007 Third-Quarter Report 3 Essilor's 2007 Third-Quarter Report 4 ASU researchers improve memory devices using nanotech 2 ASU researchers improve memory devices using nanotech 3

BIO-key(R) Awarded Contract to Deploy Incident Reporting System for Littleton, CO Police Department Essilor's 2007 Third-Quarter Report ASU researchers improve memory devices using nanotech

Caspr2 Antigen: Fusion protein amino acids 96-1265 (extracellular domain) of human Caspr2 Accession Number: NP_054860...

... Sac-Cel (Second Antibody Coated CELlulose) was ... Diagnostics of Dartford, Kent, one of the ... world. IDS acquired the product range in ... and clinical biochemists developing their own "in ...

... standard is a new tuning and calibration ... mass spectrometry. Accumix is a lyophilized ... coverage for both tuning and calibration of ... and Fourier transform mass spectrometers. Direct ...

Determin interaction of your protein with Echelons lipids...

Biology Products:

Mouse Anti-Human Caspr2 Monoclonal Antibody, Unconjugated, Clone K67/25 from UC Davis/NINDS/NIMH NeuroMab Facility Anti-Sheep/Goat Sac-Cel - Solid-phase Separation System from IDS Ltd Accumix from Protea Biosciences, Inc.PIP Microstrips from Echelon Biosciences Inc.

( otubule intermediates in the cell. ...)The making and breaking of microtubules