SCIENCE science.org 21 JANUARY 2022 • VOL 375 ISSUE 6578 280-B
RESEARCHEdited by Michael FunkALSO IN SCIENCE JOURNALS
CORONAVIRUS
Evasive maneuvers by
the spike protein
Throughout the course of the
COVID-19 pandemic, variants
have arisen in the severe acute
respiratory syndrome coronavi-
rus 2 (SARS-CoV-2) virus that
increase infectivity or reduce
its susceptibility to existing
antibodies. Nabel et al. focus on
mutations in the spike protein,
which is found on the viral
surface and is responsible for
binding and entering host cells,
and show that the structure
exhibits plasticity in resisting
neutralizing antibodies. Working
with pseudoviruses, the authors
identify combinatorial mutations
that might lead to resistance.
They identify an antibody that
neutralizes a pseudotype with a
highly mutated spike, but also
show that SARS-CoV-2 can
acquire a glycan to escape this
neutralization. Understanding
the consequences of changes in
the antigenic landscape of the
spike protein is important if we
are to rapidly respond to new
variants of concern. —VV
Science, abl6251, this issue p. 282
PROTEIN DESIGN
Designing dynamic
protein complexes
Protein complexes play
important roles in biological
processes, and many complexes
are dynamic, with subunits
exchanging to facilitate dif-
ferent functions. It has been
challenging to design stable and
soluble monomeric proteins that
reversibly associate into hetero-
oligomers. Sahtoe et al. used a
strategy called implicit negative
design to construct proteins
with interaction interfaces that
drive association with a selected
partner but not self-association.
The resulting designs are stably
folded in solution and provide
the modules for assembly into a
wide variety of complexes. They
can be functionalized, allowing
target proteins to be displayed
in defined geometries, and com-
plex subunits can be exchanged
by varying the available concen-
trations of components. —VV
Science, abj7662, this issue p. 283SYNTHETIC BIOLOGY
Building synthetic cell
fate selection
An important goal for synthetic
biology is to establish control
systems that allow the direc-
tion of cells into multiple stable
states, much like biological
signaling systems do during
organismal development. Zhu et
al. devised a system that allows
such control through designed
zinc finger transcription factors
that interact with one another
through homo- and heterodi-
merization and can be regulated
by small molecules that control
dimerization and stability of
the transcription factors (see
the Perspective by Kunze and
Khalil). Mathematical modeling
allowed computational predic-
tion of the system’s behavior,
and the introduction of three
designed transcription factors
in cultured mammalian cells
allowed direction of the cells
into seven distinct, stable states.
Understanding such multistabil-
ity is useful in synthetic biology
and can help to determine its
roles in development and dis-
ease processes. —LBR
Science, abg9765, this issue p. 284;
see also abn6548, p. 262ATTOSECOND SCIENCE
Coherent electron motion
in real time
Charge transfer plays a funda-
mental role in many chemical
and biological processes, yet
many important questions about
its mechanics at the electronic
level remain unanswered. Recent
development of attosecond x-ray
free-electron laser sources have
enabled site-specific valence
excitations in molecular systemson a time scale shorter than
the natural charge dynamics.
Li et al. use this technology to
produce coherent superposi-
tions of core-excited states in
the model molecule nitric oxide,
which is composed of biorel-
evant atoms. The authors map
the time-dependent current of
the Auger-Meitner emission by
means of an angular streaking
measurement. The present work
demonstrates the ability to use
x-ray free-electron lasers for
exploring electronic coherences
in the charge transfer on the
attosecond time scale. —YS
Science, abj2096, this issue p. 285MULTIPLE SCLEROSIS
Stronger evidence for
viral connection
Multiple sclerosis is a chronic
demyelinating disease of the
central nervous system. The
underlying cause of this disease
is not known, but Epstein-Barr
virus is thought to be a possible
culprit. However, most people
infected with this common
virus do not develop multiple
sclerosis, and it is not feasible to
directly demonstrate causa-
tion of this disease in humans.
Using data from millions of US
military recruits monitored over
a 20-year period, Bjornevik et al.
determined that Epstein-Barr
virus infection greatly increased
the risk of subsequent multiple
sclerosis and that it preceded
the development of disease,
supporting its potential role in
the pathogenesis of multiple
sclerosis (see the Perspective by
Robinson and Steinman). —YN
Science, abj8222, this issue p. 296;
see also abm7930, p. 264PEROVSKITES
Perovskite nanocrystals
under glass
Perovskite nanocrystals (PNCs)
such as cesium lead triiodide
(CsPbI 3 ) can display bright
photoemission with narrowlinewidths for display appli-
cations, but their long-term
stability requires passivation
and encapsulation steps after
synthesis in solution. Sun et
al. created three-dimensional
arrays of PNCs in doped metal
oxide glasses using ultrafast
laser pulses that caused local
melting and subsequent crystal-
lization. They tuned the bandgap
of PNCs and their photolumi-
nescence between 480- and
700-nanometer wavelengths by
transforming the composition
from CsPb(Cl1-xBrx) 3 to CsPbI 3.
These encapsulated PNCs exhib-
ited long-term stability after
prolonged heating or organic
solvent and ultraviolet light
exposure. —PDS
Science, abj2691, this issue p. 307SOCIAL PSYCHOLOGY
A kiss tells the tale
Young humans are remarkably
helpless, relying entirely on the
adult humans around them for
survival. However, not all adults
are as invested in the care of a
particular child, and there is ben-
efit in being able to determine
from a very young age which
relationships are close. Thomas
et al. tested young children and
infants to determine whether
they were able to identify close,
or “thick,” relationships based
on whether individuals partici-
pated in activities that involve
sharing saliva, such as eating,
kissing, or sharing utensils (see
the Perspective by Fawcett). The
children expected relationships
like these to be closer than other
relationships, indicating that
they can distinguish closeness
very early in life. —SNV
Science, abh1054, this issue p. 311;
see also abn5157, p. 260RESEARCH TECHNOLOGY
Sorting cells by
intracellular features
Fluorescence-activated cell
sorting, reported in Science 52
years ago, has revolutionized