Table 1.

The outcomes of viral interaction with host cell Ca²⁺ handling machinery.

Site	S. No.	Virus	Viral Protein	Host target	Effect on host cell Ca2+ signaling	Relevance to viral pathogenesis	Reference
PM	1	IAV	Hemagglutinin (HA)	VGCC	Induces intracellular Ca2+ oscillation	Helps in viral entry and replication	Fujioka et al. (2018)
	2	HIV-1	Tat	VGCC	Elevation of intracellular Ca2+	Host immune dysfunction	Zocchi et al. (1998)
	3	Flavivirus (JEV, ZIKV, DENV, YFV and WNV)	NS4B	VGCC	Increases cytosolic Ca2+	Viral replication	Wang et al. (2017)
	4	NWA	Viral glycoproteins(GP)	VGCC	Increases cytosolic Ca2+	Helps in viral entry and infection	(Lavanya et al., 2013; Sarute and Ross, 2020)
	5	HBV	HBx	Orai1	Increases cytosolic Ca2+	Essential for HBV replication	(Yao et al., 2018)
	6	HTLV-1	p12I	SOCC	Elevation of cytoplasmic Ca2+	Aids in viral replication	Ding et al. (2002)
	7	RV	NSP4	SOCC	SOCE activation, increases cytoplasmic Ca2+ levels	Aid in viral replication	(Díaz et al., 2012; Hyser et al., 2013)
	8	DENV	Not known	Orai1	Rise in cytosolic Ca2+	Viral replication	Dionicio et al. (2018)
	9	Arenavirus and Filovirus	VP40	Orai1	Rise in cytosolic Ca2+ levels	Viral budding and spread	Han et al. (2015)
	10	HIV-1	Gp120, Tat	NMDAR	Increases intracellular Ca2+	Not known	(Nath et al., 1995; Self et al., 2004)
	11	HCV, DEVN, ZIKV	Not Known	TRPV4	Rise in cytosolic Ca2+	Viral replication and exit	Doñate-Macián et al. (2018)
	12	HBV	HBx	PMCA	Elevation of the cytosolic Ca2+	Enhances HBV DNA replication and HBV core assembly	Zhou et al. (2013)
	13	RV	Not Known	NCX	Rise in cytosolic Ca2+	RV replication	Díaz et al. (2012)
ER	1	RV	NSP4	Acts as ER Viroporin	Depletes ER Ca2+ and increase in cytosolic Ca2+	Viral replication and assembly	(Díaz et al., 2008; Hyser et al., 2013; Pham et al., 2017)
	2	HCMV	US21	Acts as ER Viroporin	Depletes ER Ca2+ stores	Decreases cell susceptibility to apoptosis	Luganini et al. (2018)
	3	HCMV	UL37	IP3R	Mobilizes Ca2+ from ER to cytosol	Enhanced ATP production to meet viral energy demands	Sharon-Friling et al. (2006)
	4	HCMV	US28	Triggers PLC-β signaling	Release of intracellular Ca2+	May have role in latent infection	Miller et al. (2012)
	5	HCMV	vCXCL1	Agonist for human chemokines CXCR1 and CXCR2	Intracellular Ca2+ release	Viral dissemination through the host	(Penfold et al., 1999; Wang et al., 2003)
	6	EBV	LMP-1	SERCA3	Increase in resting cytosolic Ca2+ levels	Development of latent, persistent infection and cell immortalization	Dellis et al. (2009)
	7	HIV	Gag	IP3R	Ca2+ release from ER	Viral budding, formation of VLPs	(Ehrlich et al, 2011, 2014; Ehrlich and Carter, 2012)
	8	HIV	Nef	IP3R	Ca2+ release from ER	AIDS pathogenesis	(Ehrlich et al., 2010; Manninen and Saksela, 2002)
	9	HBV	HBx	IP3R	Increase in mitochondrial Ca2+ uptake	Aid in viral replication	Yang and Bouchard (2012)
	10	HSV	Not defined	IP3R	Increases cytosolic Ca2+	Viral penetration, delivery of viral capsids to host cell's nucleus.	(Cheshenko et al, 2003, 2007)
Mitochondria	1	HBV	HBx	mPTP	Releases Ca2+ from mitochondria	Regulates HBV replication	Bouchard et al. (2001)
	2	HCV	NS5A	MCU	Increased mitochondrial Ca2+ influx and nuclear translocation of transcription factors	Helps in viral pathogenesis	Gong et al. (2001)
	3	HCV	HCV polyprotein	MCU	Increase in mitochondrial Ca2+ influx	May induce apoptosis	Piccoli et al. (2007)
	4	HCV	Core protein	MCU	Increase in mitochondrial Ca2+ uptake	Increases ROS production and alters apoptosis	Li et al. (2007)
	5	HEV	Orf3	VDAC1	Upregulation of VDAC	Enhances viral replication	Moin et al. (2007)
	6	HIV-1	Tat	MCU	Increase in mitochondrial Ca2+ uptake	Host cell apoptosis	(Kruman II et al., 1998)
	7	HIV-1	Tat	VDAC	Rise in mitochondrial Ca2+	Host cell apoptosis	Lecoeur et al. (2012)
	8	PV	Not known	VDAC and MCU	Increase mitochondrial Ca2+ levels	Apoptosis induction	Brisac et al. (2010)
Lysosomes	1	EBOV and Marburgvirus	Not known	TPC2	Ca2+ release from lysosomes	EBOV entry and infection, Marburgvirus infection	(Penny et al., 2019; Sakurai et al., 2015; Simmons et al., 2016)
	2	Polyomavirus	Not known	TPC1/2	Ca2+ release from lysosomes	Viral entry	Dobson et al. (2020)
	3	MERS-CoV	Furin	TPCs	Ca2+ release from lysosomes	Viral entry	Gunaratne et al. (2018)
	4	SARS-CoV-2	Not known	TPC2	Ca2+ release from lysosomes	Viral entry	Ou et al. (2020)
	5	HIV-1	Tat	TRPML1	Ca2+ release from lysosomes	HIV-1 replication and latent infections	Khan et al. (2019)
Golgi	1	DENV, ZIKV, CHIKV, RSV and Measles virus	Not known	SPCA1	–	Viral maturation and exit	Hoffmann et al. (2017)
	2	AAV	Not known	SPCA1	Perturbs cytosolic Ca2+	AAV transduction	(Madigan et al., 2020; Pillay et al., 2016)