SASDBW3: Human calumenin (sarco-endoplasmic reticulum calcium-sensing protein)

Basic information

Entry

Database: SASBDB / ID: SASDBW3

Sample

Human calumenin (sarco-endoplasmic reticulum calcium-sensing protein)

• Human Calumenin (protein), CALU, Homo sapiens

Function / homology

Function:

sarcoplasmic reticulum lumen / Post-translational protein phosphorylation / Regulation of Insulin-like Growth Factor (IGF) transport and uptake by Insulin-like Growth Factor Binding Proteins (IGFBPs) / melanosome / Platelet degranulation / endoplasmic reticulum lumen / calcium ion binding / endoplasmic reticulum membrane / endoplasmic reticulum / Golgi apparatus / extracellular region / membrane

Domain/homology:

EF hand / EF-hand, calcium binding motif / EF-Hand 1, calcium-binding site / EF-hand calcium-binding domain. / EF-hand calcium-binding domain profile. / EF-hand domain / EF-hand domain pair

Component:

Calumenin

• Biological species: Homo sapiens (human)
• Citation: Journal: PLoS One / Year: 2016; Title: Ca-Dependent Folding of Human Calumenin.; Authors: Marco Mazzorana / Rohanah Hussain / Thomas Sorensen / ; Abstract: Human calumenin (hCALU) is a six EF-hand protein belonging to the CREC family. As other members of the family, it is localized in the secretory pathway and regulates the activity of SERCA2a and of the ryanodine receptor in the endoplasmic reticulum (ER). We have studied the effects of Ca2+ binding to the protein and found it to attain a more compact structure upon ion binding. Circular Dichroism (CD) measurements suggest a major rearrangement of the protein secondary structure, which reversibly switches from disordered at low Ca2+ concentrations to predominantly alpha-helical when Ca2+ is added. SAXS experiments confirm the transition from an unfolded to a compact structure, which matches the structural prediction of a trilobal fold. Overall our experiments suggest that calumenin is a Ca2+ sensor, which folds into a compact structure, capable of interacting with its molecular partners, when Ca2+ concentration within the ER reaches the millimolar range.

Contact author

• Marco Mazzorana (Diamond, Diamond Light Source, Didcot, UK)

Models

Sample

• Sample: Name: Human calumenin (sarco-endoplasmic reticulum calcium-sensing protein)
• Buffer: Name: HEPES / pH: 7.5 / Composition: 25 mM NaCl, 2.5 mM CaCl2

Entity #310

Name: CALU / Type: protein / Description: Human Calumenin / Formula weight: 29.413 / Num. of mol.: 1 / Source: Homo sapiens / References: UniProt: O43852
Sequence:

ESKERLGKIV SKIDGDKDGF VTVDELKDWI KFAQKRWIYE DVERQWKGHD LNEDGLVSWE EYKNATYGYV LDDPDPDDGF NYKQMMVRDE RRFKMADKDG DLIATKEEFT AFLHPEEYDY MKDIVVQETM EDIDKNADGF IDLEEYIGDM YSHDGNTDEP EWVKTEREQF VEFRDKNRDG KMDKEETKDW ILPSDYDHAE AEARHLVYES DQNKDGKLTK EEIVDKYDLF VGSQATDFGE ALVRHDEF

Experimental information

• Beam: Instrument name: Diamond Light Source B21 / City: Oxfordshire / 国: UK / Shape: 1 x 5 mm / Type of source: X-ray synchrotron / Dist. spec. to detc.: 3.9 mm
• Detector: Name: Pilatus 2M

Scan

Title: Human calumenin / Measurement date: Feb 12, 2016 / Storage temperature: 20 °C / Number of frames: 41 / Unit: 1/nm /

	Min	Max
Q	0.0385	4.0241

Distance distribution function P(R)

Sofotware P(R): GNOM 5.0 / Number of points: 1240 /

	Min	Max
Q	0.203437	3.60909
P(R) point	1	1240
R	0	6.54

Result

Type of curve: single_conc /

	Experimental	Porod
MW	29 kDa	30.5 kDa
Volume	-	48.8 nm3

	P(R)	Guinier	P(R) error	Guinier error
Forward scattering, I0	0.0638	0.063	-	-
Radius of gyration, Rg	2.31 nm	2.28 nm	0.02	0.29

	Min	Max
D	-	6.54
Guinier point	61	194