Keynote and Faculty Speakers

Overview

The 2019 keynote address will be given at 7:15 p.m. Friday, October 25th, at the Fayetteville Town Center.

Invited faculty talks will be given from 1:30-3:00 p.m. Friday, October 25th, in the Chancellor Hotel, Eureka Springs Ballroom, on the Fayetteville Square.  Abstracts and titles will be posted when available.

Invited student talks will be given from 3:15-5:00 p.m. Friday, October 25th, in the Chancellor Hotel, assigned rooms, on the Fayetteville Square.  (Please see the link to “Invited Student Speakers.”)

 

2019 Keynote Speaker (Friday Evening – Town Center – 7:15 pm)

  
Dr. Carrie L. Partch, Ph.D.
Department of Chemistry and Biochemistry
University of California Santa Cruz

TITLE:  Short clocks and morning larks: a structural switch in Casein Kinase 1δ controls circadian timing in humans

ABSTRACT:  Organisms adapt to the 24-hour solar cycle with molecular clocks that coordinate cellular functions with the external cue of sunlight to generate circadian rhythms of behavior and physiology. The timekeeping of these genetically encoded molecular clocks is driven by a transcription-translation feedback loop that leads to daily changes in the abundance of PERIOD (PER) proteins. Inherited mutations in PER2 lead to its premature turnover and a shorter clock, giving rise to Familial Advanced Sleep Phase Syndrome (FASPS), which is characterized by an early sleep onset and waking time (i.e., extreme morning larks). PER2 stability is largely determined by its phosphorylation state at two distinct regions within the protein, the Degron and FASP region; phosphorylation of PER2 by Casein Kinase 1 delta (CK1δ) at the Degron recruits the E3 ubiquitin ligase, β-TrCP, to induce PER2 degradation, while phosphorylation of the latter region somehow stabilizes PER2 to lengthen the clock. Understanding how CK1δ regulates these two sites on PER2 is key to understanding the molecular basis for clock periodicity. The CK1 Tau mutation (R178C), first identified in rodents with a 20-hour period, has been mapped to an anion-binding pocket near the activation loop on the kinase. We solved several high-resolution crystal structures of the wild-type CK1δ and Tau mutant to discover a two-state conformational switch in the activation loop that is coupled to anion occupancy. This conformational switch controls substrate preference, as the Tau mutant exhibits a gain of function toward the Degron and a loss of function at the FASP region using in vitro and cell-based kinase assays. MD simulations support experimental observations that the Tau mutation changes the dynamics of the kinase near the activation loop and suggest a mechanism by which other short period mutants from Drosophila to humans leverage this conformational switch in CK1 to control circadian period.

 

Faculty Speakers:

 

PHYSICS (1:35 pm Friday):

to be announced

 

BIOLOGY (2:05 pm Friday):

to be announced

 

CHEMISTRY (2:35 pm Friday):

to be announced