Humanin (HN) is a
24-residue peptide displaying a protective activity
in vitro
against a range of cytotoxic and neurotoxic insults, as well as
mediating in
vivo amelioration of Alzheimer disease (AD)-related memory
impairment in experimental models. Published evidence suggests
that the mechanisms through which HN exerts its cyto- and
neuroprotective activity may include its secretion and binding to
membrane-associated receptors. Here, we describe the
identification of a new modulator of HN neuroprotective activity,
V-set and transmembrane domain containing 2 like (VSTM2L),
previously known as C20orf102. VSTM2L interacts with HN in both
yeast and mammalian cells, is secreted in cultured cells, is
present in serum, and is selectively expressed in the central
nervous system. VSTM2L colocalizes with HN in distinct brain areas
as well as in primary cultured neurons, where it plays a role in
the modulation of neuronal viability. When tested in HN
neuroprotection bioassays, VSTM2L acts as a strong antagonist of
HN neuroprotective activity. In summary, VSTM2L is the first
example of a secreted antagonist of HN and may play a role in the
modulation of HN biological functions—Rossini, L., Hashimoto, Y.,
Suzuki, H., Kurita, M., Gianfriddo, M., Scali, C., Roncarati, R.,
Franceschini, D., Pollio, G., Trabalzini, L., Terstappen, G. C.,
Matsuoka, M., Caricasole, A. VSTM2L is a novel secreted antagonist
of the neuroprotective peptide Humanin. |