Premium
Generation of a heterodimer of NGF muteins to study the function of the putative TrkA‐p75 heteroreceptor complex
Author(s) -
Mehta Hrishikesh M,
Neet Kenneth E
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.lb285
Subject(s) - tropomyosin receptor kinase a , nerve growth factor , receptor , microbiology and biotechnology , chemistry , neurite , low affinity nerve growth factor receptor , biology , biochemistry , in vitro
Nerve growth factor (NGF), a non‐covalently bound dimer, binds two distinct receptors; TrkA (tyrosine kinase receptor family) and p75 (TNF receptor family). NGF supports survival and differentiation through these receptors and can also induce apoptosis through p75 alone. NGF also exhibits high and low affinity binding sites on cells expressing these receptors. The high affinity site is observed on cells expressing both receptors and thought to be formed by formation of a heteroreceptor complex. To study function of the heteroreceptor complex in absence of individual homoreceptor complexes we generated a heterodimer of two NGF muteins (heteromutein) such that it would not function through TrkA dimerization. Muteins Δ9/13 (9‐13aa deleted) and SS1‐NGF (7FA/H84A/R103A) form a heteromutein that, using the structural rationale, can bind only one TrkA receptor. The heteromutein should bind p75 on one side and TrkA on the other, hence be capable of forming a heteroreceptor complex. We used the heteromutein to study neurite outgrowth (TrkA function) in PC12 cells. We observe significantly higher neurite formation (55%) with the heteromutein compared to Δ9/13 (2%) and SS1‐NGF (30%) at 2 nM. The heteromutein (2 nM) also gave wild type levels of survival for PC12 cells. Our study supports a possible function for the heteroreceptor complex in augmenting neuritogenesis, and perhaps survival. (Supported by NIH grant NS24380)