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
