NIF LinkOut Portal

Options
Only Pubmed Central
Include Pubmed Central
Sections
Title
Abstract
Introduction
Methods
Results
Supplement
Appendix
Contributions
Background
Commentary
Funding
Limitations
Caption
FILTERS

The adapter protein CrkL associates with CD34.

Authors:
Felschow DM, McVeigh ML, Hoehn GT, Civin CI, Fackler MJ
Affiliation:
Journal:
Blood

Abstract

CD34 is a cell-surface transmembrane protein expressed specifically at the stem/progenitor stage of lymphohematopoietic development that appears to regulate adhesion. To elucidate intracellular signals modified by CD34, we designed and constructed glutathione-S-transferase (GST)- fusion proteins of the intracellular domain of full-length CD34 (GST-CD34i(full)). Precipitation of cell lysates using GST-CD34i(full) identified proteins of molecular mass 39, 36, and 33 kd that constitutively associated with CD34 and a 45-kd protein that associated with CD34 after adhesion. By Western analysis, we identified the 39-kd protein as CrkL. In vivo, CrkL was coimmunoprecipitated with CD34 using CD34 antibodies, confirming the association between CrkL and CD34. CD34 peptide inhibition assays demonstrated that CrkL interacts at a membrane-proximal region of the CD34 tail. To identify the CrkL domain responsible for interaction with CD34, we generated GST-fusion constructs of adapter proteins including GST-CrkL3' (C-terminal SH3) and GST-CrkL5' (N-terminal SH2SH3). Of these fusion proteins, only GST-CrkL3' could precipitate endogenously expressed CD34, suggesting that CD34 binds the C-terminal SH3 domain of CrkL. Interestingly, there appears to be differential specificity between CrkL and CrkII for CD34, because GST-CD34i(full) did not precipitate CrkII, a highly homologous Crk family member. Furthermore, GST-CD34i(full) did not bind c-Abl, c-Cbl, C3G, or paxillin proteins that are known to associate with CrkL, suggesting that CD34 directly interacts with the CrkL protein. CD34i(full) association with Grb or Shc adapter proteins was not detected. Our investigations shed new light on signaling pathways of CD34 by demonstrating that CD34 couples to the hematopoietic adapter protein CrkL. (Blood. 2001;97:3768-3775)

  1. Welcome

    Welcome to NIF. Explore available research resources: data, tools and materials, from across the web

  2. Community Resources

    Search for resources specially selected for NIF community

  3. More Resources

    Search across hundreds of additional biomedical databases

  4. Literature

    Search Pub Med abstracts and full text from PubMed Central

  5. Insert your Query

    Enter your search terms here and hit return. Search results for the selected tab will be returned.

  6. Join the Community

    Click here to login or register and join this community.

  7. Categories

    Narrow your search by selecting a category. For additional help in searching, view our tutorials.

  8. Query Info

    Displays the total number of search results. Provides additional information on search terms, e.g., automated query expansions, and any included categories or facets. Expansions, filters and facets can be removed by clicking on the X. Clicking on the + restores them.

  9. Search Results

    Displays individual records and a brief description. Click on the icons below each record to explore additional display options.

X