©cmbi 2006 molecular motors at the organism – population level, motors are needed to transfer...
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©CMBI 2006
Molecular motors
At the organism – population level, motors are needed to transfer materials.
At the organelle – organ level, motors are needed to transfer material and information.
©CMBI 2006
Slides borrowed from:
http://mc11.mcri.ac.uk/motorhome.htmlhttp://valelab.ucsf.edu/movies/movies.htmlhttp://www.people.virginia.edu/~rjl6n/dynein.htmhttp://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/http://www.cytochemistry.net/Cell-biology/http://www.ks.uiuc.edu/Research/cell_motility/http://nature.berkeley.edu/~hongwang/Project/
©CMBI 2006
Motors
©CMBI 2006
Kinesin - Dynein
Kinesin: Most members of the kinesin family of motor proteins walk along microtubules away from the centrosome. Dynein: The dyneins walk along microtubules toward the centrosome).
©CMBI 2006
The Tubulin Autobahn
In the cell itself, microtubules are formed in an area near the nucleus called the "aster". This is also called the Microtubule Organizing Center (MTOC). Microtubules are polar with a plus end (fast growing) and a minus end (slow growing). Usually the minus end is the anchor point in the MTOC. In this figure, the plus end is shown to the left by the numerous tubulin dimers. This is the end that carries the GTP molecules which may be hydrolyzed to GDP.
©CMBI 2006
Actin - Myosin
©CMBI 2006
Perpetual motion - A/GTP
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G proteins do it with GTP
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Cholesterol transport
©CMBI 2006
Information transfer
Information flows through our body in many different ways.One method is to send out messengers (hormones) that can be recognized by other cells or organs.GPCRs and nuclear receptors are examples of receptors for this type of information.
©CMBI 2006
Rule 1
First rule of sequence analysis:
If a residue is conserved, it is important.
©CMBI 2006
Rule 2
Second rule of sequence analysis:
If a residue is very conserved, it is very important.
©CMBI 2006
Sequence Entropy
20
Ei = pi ln(pi) i=1
©CMBI 2006
Sequence Variability
Sequence variability is the number of residues that is present in more than 0.5% of all sequences.
©CMBI 2006
Entropy - Variability
Variability is result of evolution.
Entropy is the protein’s break on evolutionary speed.
©CMBI 2006
GPCR Entropy - Variability
11 Red12 Orange22 Yellow23 Green33 Blue
©CMBI 2006
GPCR Location
11 Red12 Orange22 Yellow23 Green33 Blue
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Ras Entropy - Variability
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Ras Location
11 Red12 Orange22 Yellow23 Green33 Blue
©CMBI 2006
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