Monomeric G-protein: Difference between revisions

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&nbsp; A monomeric G-protein ( also known as small G protein or small GTPases, is the umbrella term for a family of signal transducing proteins. These comprise of: Rab, Arf, Ras, Ran and Rho, which are also vital in the growth of cells, as well as cell transport, motility, cytokinesis and cell differentiation.<ref>Berg et al., (2006) Biochemistry, 6th edition, New York. Pages 432</ref>&nbsp;Monomeric G proteins comprise of two forms, 1.) an 'inactive' form in which the monomeric G-protein is bound to GDP ( guanosine diphosphate), and 2.) the 'active' &nbsp;form in which the Monomeric G-protein is bound to GTP ( guanosine triphosphate). Notably, Monomeric&nbsp;G-proteins are small,( ranging around 20-25 Kd,) compared with larger types of G protein like Heterotrimeric proteins ( which are typically 30-35 Kd). <br> <br> <br> <br> References:&nbsp;
A monomeric [[G-protein|G-protein]] (also known as small G protein or small [[GTPase|GTPases]], is the umbrella term for a family of [[signal transducing proteins|signal transducing proteins]]. These comprise of: [[Rab|Rab]], [[Arf|Arf]], [[Ras|Ras]], [[Ran|Ran]] and [[Rho|Rho]], which are also vital in the growth of cells, as well as cell transport, motility, [[Cytokinesis|cytokinesis]] and [[Cell differentiation|cell differentiation]]<ref>Berg et al., (2006) Biochemistry, 6th edition, New York. Pages 432</ref>.&nbsp;Monomeric G proteins comprise of three forms:
 
#an 'inactive' form in which the monomeric G-protein is bound to [[GDP|GDP]] ([[Guanosine diphosphate|guanosine diphosphate]]), and
#In order to activate the inactive form of monomeric G-protein, a guanine exchange factor is needed.
#the 'active' &nbsp;form in which the Monomeric G-protein is bound to [[GTP|GTP]] ([[Guanosine triphosphate|guanosine triphosphate]]).
 
Notably, monomeric&nbsp;G-proteins are small (ranging around 20-25 kDa) compared with larger types of G protein like [[Heterotrimeric G-proteins|heterotrimeric]] proteins (which are typically 30-35 kDa)<ref>Berg et al., (2006) Biochemistry, 6th edition, New York. Pages 433</ref>. To inactivate a monomeric G protein,&nbsp;a [[GTPase activating protein|GTPase activating protein]] (GAP) is required to hydrolyse the GTP to GDP as they have weak intrinsic [[GTPase activity|GTPase activity]].
 
=== References:&nbsp; ===
 
<references />

Latest revision as of 07:57, 28 November 2016

A monomeric G-protein (also known as small G protein or small GTPases, is the umbrella term for a family of signal transducing proteins. These comprise of: Rab, Arf, Ras, Ran and Rho, which are also vital in the growth of cells, as well as cell transport, motility, cytokinesis and cell differentiation[1]. Monomeric G proteins comprise of three forms:

  1. an 'inactive' form in which the monomeric G-protein is bound to GDP (guanosine diphosphate), and
  2. In order to activate the inactive form of monomeric G-protein, a guanine exchange factor is needed.
  3. the 'active'  form in which the Monomeric G-protein is bound to GTP (guanosine triphosphate).

Notably, monomeric G-proteins are small (ranging around 20-25 kDa) compared with larger types of G protein like heterotrimeric proteins (which are typically 30-35 kDa)[2]. To inactivate a monomeric G protein, a GTPase activating protein (GAP) is required to hydrolyse the GTP to GDP as they have weak intrinsic GTPase activity.

References: 

  1. Berg et al., (2006) Biochemistry, 6th edition, New York. Pages 432
  2. Berg et al., (2006) Biochemistry, 6th edition, New York. Pages 433