|Protein Name||Voltage-dependent L-type calcium channel subunit beta-2|
|Milk Fraction||MFGM, Exosome|
|Ref Sequence ID||NP_786983.1|
|Protein Existence Status||Reviewed: Experimental evidence at transcript level|
|Presence in other biological fluids/tissue/cells||expressed in brain, heart, lung, nerve endings at the neuro-muscular junction, T-cells, osteoblasts and other tissues|
|Protein Function||cytosolic auxiliary subunit that plays an essential role in regulating the surface expression and gating properties of high-voltage activated (HVA) Ca2+ channels; crucial for the modulation of HVA Ca2+ channels by G proteins, kinases, Ras-related RGK GTPases, and other proteins; crucial for the modulation of HVA Ca2+ channels by G proteins, kinases, Ras-related RGK GTPases, and other proteins; critical for the regulation of VGCC by lipids, G-proteins, RGK GTPases; required for normal channel expression;|
|Biochemical Properties||The amino and carboxyl termini of Cavβ (abbreviated as Cavβ-NT and Cavβ-CT) are highly variable; binds with high affinity to the pore-forming α1 subunit (Cavα1) of voltage-gated calcium channels; Cavβ-Guanylate kinases domain is catalytically inactive; SH3 and GK domains interact intramolecularly; susceptible to several kinds of inhibition by hormones and neurotransmitters through the activation of G-protein coupled receptors- most prominent type of inhibition is the membranedelimited, voltage-dependent inhibition mediated by the direct binding of G protein Gβγ subunits to the channel’s α1 subunit;|
|Significance in milk||might paly a role in the entry of calcium in mammary epithelial cells|
|PTMs||Glycosylated: Four potential Nglycosylation sites are present in the rabbit Cav1.2 channel and located in the domain I (N124 and N299) and domain IV (N1359 and N1410)|
| Site(s) of PTM(s) |
|>sp|Q9MZL5|CACB2_BOVIN Voltage-dependent L-type calcium channel subunit beta-2 OS=Bos taurus OX=9913 GN=CACNB2 PE=2 SV=1|
MQCCGLVHRR RARVSYGSAD SYTSRPSDSD VSLEEDREAV RREAERQAQA QLEKAKTKPV AFAVRTNVSY SAAHEDDVPV PGMAISFEAK DFLHVKEKFN NDWWIGRLVK EGCEIGFIPS PVKLENMRLQ HEQRAKQGKF YSSKSGGNS*149S SS*152LGDIVPSS RKS*163TPPSSAI DIDATGLDAE DNDIPANHRS PKPSANSVTS PHSKEKRMPF FKKTEHTPPY DVVPSMRPVV LVGPSLKGYE VTDMMQKALF DFLKHRFEGR ISITRVTADI SLAKRSVLNN PSKHAIIERS NTRSSLAEVQ SEIERIFELA RTLQLVVLDA DTINHPAQLS KTSLAPIIVY VKISSPKVLQ RLIKSRGKSQ AKHLNVQMVA ADKLAQCPPE LFDVILDENQ LEDACEHLAD YLEAYWKATH PPSSSLPNPL LSRTLATSTL PVSPTLASNS QGSQGDQRTD RGAPGRSASQ AEEEHCPEPV KKAQHRSSTQ HHNHRSGTSR GLS*493RQET*497LDS ETQESRDSAY AEPKEEYSHE HADHYAPHRD HNHREEPHGG GEHRHREPRH RSRDPDREQD HNESNKQRSR HKSKDRYCDK DGEGLSRRRN EAADWNRDVY IRQ
|Predicted Disorder Regions||135-206,432-603|
|TM Helix Prediction||No TM helices|
|Significance of PTMs||N-glycosylation of Cav1.2 serves distinct roles in the expression of the channel protein at the cell surface and also in the control of the gating properties of the channel|
|Bibliography||1. Park, H.-J. et al. (2015) ‘Asn-Linked Glycosylation Contributes to Surface Expression and Voltage-Dependent Gating of Cav1.2 Ca2+ Channel.’, Journal of microbiology and biotechnology, 25(8), pp. 1371–9. doi: 10.4014/jmb.1501.01066. |
2. VanHouten, J. N., Neville, M. C. and Wysolmerski, J. J. (2007) ‘The Calcium-Sensing Receptor Regulates Plasma Membrane Calcium Adenosine Triphosphatase Isoform 2 Activity in Mammary Epithelial Cells: A Mechanism for Calcium-Regulated Calcium Transport into Milk’, Endocrinology, 148(12), pp. 5943–5954. doi: 10.1210/en.2007-0850.
3. Buraei, Z. and Yang, J. (2010) ‘The β Subunit of Voltage-Gated Ca 2+ Channels’, Physiological Reviews, 90(4), pp. 1461–1506. doi: 10.1152/physrev.00057.2009.
4. Chen, Y. et al. (2004) ‘Structural basis of the α1–β subunit interaction of voltage-gated Ca2+ channels’, Nature, 429(6992), pp. 675–680. doi: 10.1038/nature02641.
5. Ikeda, S. R. (1996) ‘Voltage-dependent modulation of N-type calcium channels by G-protein β γsubunits’, Nature, 380(6571), pp. 255–258. doi: 10.1038/380255a0.