# Biochemical and Biophysical Tuning of Presynaptic Function by the Clock Protein BMAL1

> **NIH NIH F30** · HARVARD MEDICAL SCHOOL · 2024 · $53,974

## Abstract

Project Summary
The circadian system is an ancient mechanism which evolved in organisms to adaptively align internal state
with environmental cues. It is comprised of a molecular oscillator in every cell which, through rhythmic gene
expression, regulates predictable behavioral plasticity that is engendered by rhythmic synaptic function. The
spatiotemporal segregation of the synapse from the soma precludes the molecular oscillator from being the
mechanistic provenance for rhythmic synaptic processes and has warranted investigation for a local synaptic
clock. The Lipton lab identified that BMAL1 – a core component of the circadian mechanism – is rhythmically
localized to synapses where it interacts with the synaptic kinase Ca2+/calmodulin-dependent kinase (CaMKII⍺)
and organizes the circadian assembly of synaptic vesicle pools. The diurnal localization of BMAL1 to the
synapse is lost in a phosphoincompetent mouse model (Bmal-S42A) which also loses circadian dynamics of
synaptic vesicle clusters paired with impaired learning and memory. These findings link the circadian system to
the regulation of synaptic plasticity and synapse generated behavior, in a manner which is independent of the
core transcriptional clock. It remains unknown how BMAL1, either through biochemical and/or biophysical
mechanisms, rhythmically assembles synaptic vesicle pools in phase with circadian time. The overarching
goal of this proposed work is to gain insight into how the circadian clock biochemically and
biophysically assembles synaptic vesicles in a manner which regulates their circadian
compartmentalization and dynamics. With two related but independent aims, this proposal investigates the
biochemical interactions that BMAL1 makes with the synaptic kinase CaMKII⍺, the biomolecular condensation
of that interaction and the presynaptic signals that are BMAL1-dependent for their plasticity. Aim 1 proposes to
define the structural elements in the BMAL1 and CaMKII⍺ protein sequences which are required for their
interactions. This will be accomplished by conducting a series of complementary in vitro assays in cells and
with recombinant protein that assess interaction of these proteins and condensation of these proteins into
phase separated liquid-like droplets. The effect of these biochemical and biophysical interactions on synaptic
vesicles will then be evaluated using a non-neuronal system which reconstitutes synaptic vesicle-like
structures in both form and function. Aim 2 will then identify the presynaptic, neuromodulator systems which
require and recruit pBMAL1(S42) for their acute presynaptic plasticity control on synaptic vesicles. A screen for
neuromodulators which depend on pBMAL1(S42) for synaptic vesicle control will be conducted. Signaling
experiments will then be performed in cultured neurons and in vivo to determine if the neuromodulator
serotonin, a key regulator of rhythms and sleep/wake, potentiates pBMAL1 (S42). Such collective knowledge
gained from this pro...

## Key facts

- **NIH application ID:** 10925175
- **Project number:** 5F30MH132277-03
- **Recipient organization:** HARVARD MEDICAL SCHOOL
- **Principal Investigator:** Nicole Marie Gilette
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $53,974
- **Award type:** 5
- **Project period:** 2022-09-30 → 2025-09-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10925175

## Citation

> US National Institutes of Health, RePORTER application 10925175, Biochemical and Biophysical Tuning of Presynaptic Function by the Clock Protein BMAL1 (5F30MH132277-03). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10925175. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*