Under copyright Constraint(s) on Use: This work is protected by the U.S. Copyright Law (Title 17, U.S.C.). Use of this work beyond that allowed by "fair use" or any license applied to this work requires written permission of the copyright holder(s). Responsibility for obtaining permissions and any use and distribution of this work rests exclusively with the user and not the UC San Diego Library. Inquiries can be made to the UC San Diego Library program having custody of the work. Use: This work is available from the UC San Diego Library. This digital copy of the work is intended to support research, teaching, and private study.
Rights Holder and Contact
UC Regents
Description
This is one of six images in Figure 6 in Apaja et al., JCB 2010 that shows the fate of various model membrane proteins, that are either folded or in the unfolded state at the plasma membrane, expressed in stable tetracycline-inducible Flp-In T-Rex HEK293 cell lines. The three model membrane proteins were chimeras of the CD4 surface receptor consisting of 1.) a C-terminally truncated CD4 that contained a flexible cytoplasmic linker (CD4tl), 2.) a CD4tl fused to the N-terminal DNA-binding domain of the wild type bacteriophage lambda repressor (CD4tl-lambda), and 3.) a CD4tl fused to a L57C mutant lambda repressor (CD4tl-lambdaC). The CD4tl-lambdaC cytosolic domain was largely in native state at 26°C but predominantly nonnative state at 37°C thus allowing the use of thermal shifts to follow the fate of unfolded proteins. To examine the post-endocytic distribution of CD4 chimeras, membrane proteins were labeled by CD4 Ab capture for 20 mins in live cells at 37°C and chased for 1 h in the absence of extracellular Ab before fixation and labeling with secondary antibody to localize the internalized CD4 chimeras (green). Endosomes were labeled with 10 µg/ml Alexa Fluor 594-labeled transferrin uptake for 1 h at 37°C (red). Fluorescence micrographs were obtained by a confocal microscope (LSM510 or LSM710; Carl Zeiss, Inc.) equipped with a Plan-Apochromat 63×/NA 1.4 objective in multitrack mode. This single optical section shows that internalized CD4tl protein co-localizes with endosomes, like other plasma membrane receptors. This contrasts with the behavior of the internalized, unfolded mutant CD4tl-lambdaC, seen in a companion image in this group. Research Data Curation Program, UC San Diego, La Jolla, 92093-0175 (https://lib.ucsd.edu/rdcp) Apaja, Pirjo M.; Xu, Haijin; Lukacs, Gergely L. (2021). CIL:13689, Homo sapiens. In Cell Image Library. UC San Diego Library Digital Collections. Dataset. https://doi.org/10.6075/J0M907CZ
Type
image
Identifier
ark:/20775/bb13718218
Language
No linguistic content
Subject
293 Receptor internalization Response to unfolded protein Early endosome Plasma membrane Homo sapiens Cell Image Library Group ID: 7856
If you're wondering about permissions and what you can do with this item, a good starting point is the "rights information" on this page. See our terms of use for more tips.
Share your story
Has Calisphere helped you advance your research, complete a project, or find something meaningful? We'd love to hear about it; please send us a message.
