Calcium Signaling I Flashcards
Most calcium in the body is trapped in ______, complexed with inorganic phosphate ________
bone
hydroxyapatite
The Calcium-sensing receptor (CaSR) is expressed by _________
chief cells of the
parathyroid gland, and certain
cells of the kidney
Ca2+ is the ligand for a GPCR dimer
that can activate _____ and _______
Gq/11 and Gi
[Ca2+] in plasma is maintained between ______and ____ mM
1.1 and 1,4
An endocrine system involved in Ca signaling as extracellular signaling
Parathyroid Hormone (PTH), Vitamin D, others
Binding of _________ ions and ___________ ions to proteins is a
universal aspect of _______ signal transduction
calcium ions and phosphate ions
intracellular signal
what is the difference between phosphate and calcium
phosphate removal from ATP and its covalent
attachment to a protein.
Ionic Ca2+ binding to proteins does not rely on enzymes. It can be regulated by
alterations in [Ca2+]i
________________ respond
to binding of Ca2+ by changing their
fluorescence properties
Fluorescent Ca2+ indicators
what are the two types of Fluorescent Ca2+ indicators
Chemical indicators
and
Genetically encoded indicators
Fluorescent Ca2+ indicators are Useful for either ________ (to
quantify) or _______(to localize)
changes in [Ca2+]
photometry (to quantify) or imaging (to localize)
Choosing an indicator for measuring [Ca2+] in cytosol
range (0.1 to 1 µM)
Use a high affinity indicator, e.g. Fura-2 (Kd = 0.22 µM) or Indo-1 (Kd = 0.25 µM)
Choosing an indicator for measuring [Ca2+] in ER
range of 100 to 800 μM
Use a low affinity indicator, e.g. mag-Fura-2 (Kd = 53 µM) or mag-Indo-1
(Kd = 35 µM); a Kd between 100 and 800 µM would be even better
Choosing an indicator for measuring [Ca2+] in mitochondria
range (0.1 to 1 µM)
Use a high affinity indicator with a net positive charge, e.g. Rhod-2 (Kd = 0.57 µM)
Ca2+ binding domains of proteins
C2 domain and EF hand domain
what is the structure of C2 domain
An “8-stranded β-sandwich” composed of two antiparallel β sheets
connected by variable loops
what does C2 domain does?
C2 domain to favor interaction with anionic
membrane lipids - membrane targeting
what domain of PKC subfamilies is conserved?
catalytic
which subtype of PKC has C1 domain
both conventional and novel
which subtype of PKC has C2 domain
conventional
which subtype of PKC has C2 like domain
novel
what are the activators for PKC subtypes
conventional
novel
atypical
conventional: Dag Ca
Novel: Dag
Atypical: PIP3, Par6-CDC42
