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

Human or mammalian heart, HUMA N HEART (MAMMALIAN HEART) - Position -...

HUMA N HEART (MAMMALIAN HEART) - Position - Situated in thoracic cavity in pericardial cavity close to its front wall. Its broad base faces upward and backward. Its narrow a

Reproduction, name the sturcture formed when the male and female nuclei fus...

name the sturcture formed when the male and female nuclei fuse during fertilisation.

Explain fluids, Explain Fluids Fluids: Fluid diets are given to patien...

Explain Fluids Fluids: Fluid diets are given to patients with more advanced dysphasia or fractured jaws. The diet may include fruit juices, thin strained porridge with milk, e

What is glucose intolerance and diabetes, What is Glucose Intolerance and D...

What is Glucose Intolerance and Diabetes ? Insulin resistance, by perinsulinaemia and glucose intolerance appear to promote atherosclerosis. The prevalence of CAD raises from 2

Response to cold - responses of plants to stress, Response to Cold - Respon...

Response to Cold - Responses of Plants to Stress Let us first see what happen to a plant when it is exposed to a cold climate with temperatures below 0°C. If the temperature i

In which parts of the circulatory system are there valves, In which parts o...

In which parts of the circulatory system are there valves? There are valves in the heart (between each atrium and ventricle, in the aorta and pulmonary artery), in some of the

Explain microtube and hedstorm file removal technique, Explain Microtube an...

Explain Microtube and Hedstorm file removal technique A Hedstorm file was then passed down the length of the tube until it engaged itself tightly between the obstruction an

Explain skin changes during kwashiorkor, Explain Skin changes During Kwashi...

Explain Skin changes During Kwashiorkor? In many cases, dermatosis (changes in skin) is seen. Such changes are common in areas of friction. Dark pigmented patches, akin to sun-

Explain threaded implants, Q. Explain threaded implants? Cylindrical no...

Q. Explain threaded implants? Cylindrical non-threaded implants poorly distribute compressive forces and generate shears forces that may fragment and break the bone surrounding

Thalassemia, Thalassemia   Thalassemias are the commonest hemolytic ana...

Thalassemia   Thalassemias are the commonest hemolytic anaemias or disorder seen in children in India. This is characterised by deficiency  in the synthesis  of one of the norm

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