Define lipid-anchored proteins, Biology

Assignment Help:

A large number of integral proteins in eukaryotes do not traverse the membrane but are anchored in one or other leaflet of the bilayer through covalent attachment to a hydrocarbon chain. Several proteins, having the prion protein the causative  agent  of  mad  cow  disease  are  stably anchored  at  the  cell  surface by  covalent  linkage  of their  C-terminal  amino  acid  to the  headgroup  of a   phosphatidylinositol   lipid   by   an   ethanolamine-phosphate-trimannose-glucosamine   bridge,  so-called GPI (glycosyl  phosphatidylinositol)-anchored proteins. This difficult structure is built up by sequential addition of the individual sugar residues and ethanolamine phosphate to phosphatidylinositol. The C-terminal hydrophobic signal peptide is deleted from the protein in the lumen of the RER and the preformed GPI anchor added to the new exposed C- terminal amino acid.

2294_22.png

 

figure: Lipid-modified proteins. (a) A glycosyl phosphatidylinositol-anchored protein (G, glucosamine; M, mannose; EtP, ethanolamine phosphate); (b) A myristoylated protein; (c) A prenylated protein; (d) a palmitoylated protein. Some proteins are also customized on Cys residues with covalently attached palmitate (C16:0) (palmitoylated proteins). These have some with membrane-spanning polypeptides (fig. 2d), some prenylated proteins and some myristoylated  proteins. Various of the proteins having in cell signaling, like as the G proteins and the Ras family of proteins are lipid modified.

 

 


Related Discussions:- Define lipid-anchored proteins

Defects of nervous system, DEFECT S OF NERVOUS SYSTEM - 1.      Ataxi...

DEFECT S OF NERVOUS SYSTEM - 1.      Ataxia - Lack of muscle-cordination due to damage of cerebellum. 2.      Dyslexia - In ability of a person to comprehense written l

Respiration in annelids, Describe the different types of respiratory organs...

Describe the different types of respiratory organs found in annelids.

Epidemiology, The epidemiology of acute rheumatic fever (ARF) is closely co...

The epidemiology of acute rheumatic fever (ARF) is closely connected with that of group-A beta haemolytic streptococcal pharyngitis, both have a maximum incidence in the age group

Explain environmental sampling - methods and techniques, Explain Environmen...

Explain Environmental Sampling - Methods and Techniques? Environmental sampling can be done for total microbial load or for some specific pathogens or spoilage organisms. The m

Illustrate meiosis ii and meiosis i, Q. How many cells are made after meios...

Q. How many cells are made after meiosis II and meiosis I? After meiosis II four cells are created, After Meiosis I two cells with already separated homologous are created

Phylum platyhelminyhes, general classification of phylum platy helminthes

general classification of phylum platy helminthes

What does ecological niche of an organism represent, What does ecological n...

What does ecological niche of an organism represent? Mention the scientific term used for modified form of reproduction in which seeds are produced without fusion of gametes.

Define the post-herbal period, Define the Post-Herbal Period? It is di...

Define the Post-Herbal Period? It is difficult to draw a sharp line of demarcation between the transition period, marked by various attempts of classification, all of which we

Explain the differance between savanna and desert, Explain the differance b...

Explain the differance between savanna and desert? Savanna : Savanna is characterized by relatively low rainfall and pronounced dry seasons. This type of climate produces a b

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd