Russell body inducing threshold depends on the variable domain sequences of individual human IgG clones and the cellular protein homeostasis.

Authors:
Haruki Hasegawa, PhD
Haruki Hasegawa, PhD
Amgen Inc.
Principal Scientist
Protein trafficking Protein biosynthesis
South San Francisco, CA | United States

Biochim Biophys Acta 2012 Oct 20;1823(10):1643-57. Epub 2012 Jun 20.

Department of Therapeutic Discovery, Amgen Inc., Seattle, WA 98119, USA.

Russell bodies are intracellular aggregates of immunoglobulins. Although the mechanism of Russell body biogenesis has been extensively studied by using truncated mutant heavy chains, the importance of the variable domain sequences in this process and in immunoglobulin biosynthesis remains largely unknown. Using a panel of structurally and functionally normal human immunoglobulin Gs, we show that individual immunoglobulin G clones possess distinctive Russell body inducing propensities that can surface differently under normal and abnormal cellular conditions. Russell body inducing predisposition unique to each immunoglobulin G clone was corroborated by the intrinsic physicochemical properties encoded in the heavy chain variable domain/light chain variable domain sequence combinations that define each immunoglobulin G clone. While the sequence based intrinsic factors predispose certain immunoglobulin G clones to be more prone to induce Russell bodies, extrinsic factors such as stressful cell culture conditions also play roles in unmasking Russell body propensity from immunoglobulin G clones that are normally refractory to developing Russell bodies. By taking advantage of heterologous expression systems, we dissected the roles of individual subunit chains in Russell body formation and examined the effect of non-cognate subunit chain pair co-expression on Russell body forming propensity. The results suggest that the properties embedded in the variable domain of individual light chain clones and their compatibility with the partnering heavy chain variable domain sequences underscore the efficiency of immunoglobulin G biosynthesis, the threshold for Russell body induction, and the level of immunoglobulin G secretion. We propose that an interplay between the unique properties encoded in variable domain sequences and the state of protein homeostasis determines whether an immunoglobulin G expressing cell will develop the Russell body phenotype in a dynamic cellular setting.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbamcr.2012.06.015DOI Listing

Still can't find the full text of the article?

We can help you send a request to the authors directly.
October 2012
3 Reads
7 Citations

Publication Analysis

Top Keywords

russell body
36
variable domain
24
domain sequences
16
immunoglobulin clones
12
russell bodies
12
russell
12
chain variable
12
body inducing
12
immunoglobulin
10
properties encoded
8
immunoglobulin clone
8
protein homeostasis
8
immunoglobulin biosynthesis
8
body
8
heavy chain
8
variable
7
domain
6
clones
5
chain
5
body propensity
4

Similar Publications