Glycoprotein that help Cell Adhesion - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 04-01-2011
USMLE Forums Scout
 
Steps History: Not yet
Posts: 19
Threads: 7
Thanked 18 Times in 7 Posts
Reputation: 28
Question Glycoprotein that help Cell Adhesion

I have a question and I hope you can help.
Which glycoprotein plays a role in cell adhesion?
-selectin
-integrin b1
-integrin b2
-laminin
-fibronectin

and why?
Thank you
Reply With Quote Quick reply to this message
The above post was thanked by:
aktorque (04-01-2011)



  #2  
Old 04-01-2011
USMLE Forums Guru
 
Steps History: Step 1 Only
Posts: 487
Threads: 95
Thanked 1,466 Times in 358 Posts
Reputation: 1476
Arrow

Selectins are a family of cell adhesion molecules. All selectins are single-chain transmembrane glycoproteins that share similar properties to C-type lectins due to a related amino terminus and calcium-dependent binding. Selectins bind to sugar moieties and so are considered to be a type of lectin, cell adhesion proteins that bind sugar polymers

There are three subsets of selectins:

E-selectin (in endothelial cells)
L-selectin (in leukocytes)
P-selectin (in platelets and endothelial cells)


Function

During an inflammatory response, stimuli such as histamine and thrombin cause endothelial cells to mobilize P-selectin from stores inside the cell to the cell surface. In addition, cytokines such as TNF-alpha stimulate the expression of E-selectin and additional P-selectin a few hours later.

As the leukocyte rolls along the blood vessel wall, the distal lectin-like domain of the selectin binds to certain carbohydrate groups presented on proteins (such as PSGL-1) on the leukocyte, which slows the cell and allows it to leave the blood vessel and enter the site of infection. The low-affinity nature of selectins is what allows the characteristic "rolling" action attributed to leukocytes during the leukocyte adhesion cascade.

The best-characterized ligand for the three selectins is P-selectin glycoprotein ligand-1 (PSGL-1), which is a mucin-type glycoprotein expressed on all white blood cells.

Neutrophils and eosinophils bind to E-selectin. One of the reported ligands for E-selectin is the sialylated Lewis X Ag (sLe(x)). Eosinophils, like neutrophils, use sialylated, protease-resistant structures to bind to E-selectin, although the eosinophil expresses much lower levels of these structures on its surface. Ligands for P-selectin on eosinophils and neutrophils are similar sialylated, protease-sensitive, endo-beta-galactosidase-resistant structures, clearly different than those reported for E-selectin, and suggest disparate roles for P-selectin and E-selectin during recruitment during inflammatory responses.
Reply With Quote Quick reply to this message
The above post was thanked by:
anupreet (04-01-2011), donofitaly (04-01-2011), im99 (04-02-2011), mayankkaushal (05-16-2013), Mondoshawan (04-01-2011), rah_mem (04-02-2011), vikash (04-02-2011)
  #3  
Old 04-01-2011
USMLE Forums Guru
 
Steps History: Step 1 Only
Posts: 487
Threads: 95
Thanked 1,466 Times in 358 Posts
Reputation: 1476
Arrow

Integrins are receptors that mediate attachment between a cell and the tissues surrounding it, which may be other cells or the extracellular matrix (ECM). They also play a role in cell signaling and thereby regulate cellular shape, motility, and the cell cycle.

Typically, receptors inform a cell of the molecules in its environment and the cell responds. Not only do integrins perform this outside-in signalling, but they also operate an inside-out mode. Thus, they transduce information from the ECM to the cell as well as reveal the status of the cell to the outside, allowing rapid and flexible responses to changes in the environment, for example to allow blood coagulation by platelets.

There are many types of integrin, and many cells have multiple types on their surface. Integrins are of vital importance to all animals and have been found in all animals investigated, from sponges to mammals. Integrins have been extensively studied in humans.

Integrins work alongside other proteins such as cadherins, Immunoglobulin superfamily cell adhesion molecules, selectins and syndecans to mediate cell-cell and cell-matrix interaction and communication. Integrins bind cell surface and ECM components such as fibronectin, vitronectin, collagen, and laminin.
Reply With Quote Quick reply to this message
The above post was thanked by:
anupreet (04-01-2011), donofitaly (04-01-2011), im99 (04-02-2011), Mondoshawan (04-01-2011)



Reply

Tags
Cell-Biology-, Histology-

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Leukocyte Adhesion Defect Types? drsmar USMLE Step 1 Forum 2 03-20-2012 08:36 PM
Basic sciences: Lithium and leukocyte adhesion molecules schiwei USMLE Step 1 Forum 2 11-28-2010 05:32 PM
Basic Science - Adhesion Mechanisms schiwei USMLE Step 1 Forum 0 11-28-2010 04:02 PM
T cell defect anoop_1198 USMLE Step 2 CK Forum 6 05-25-2010 10:49 PM
Which Cell surface adhesion? USMLE123 USMLE Step 1 Forum 1 12-16-2009 09:03 AM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)