Table 1.

Structural and functional differences between HTLV-1 and HTLV-2 gene products.

Structural and functional properties	Viral proteins		Reference
	HTLV-1	HTLV-2
	Tax-1	Tax-2
LZR (leucine zipper domain)	+	-	Higuchi and Fujii (2009)
p100 binding	+	-	Shoji et al. (2009)
PDZ domain	+	-	Suzuki et al. (1999)
CD4 + immortalization	+	++	Imai et al. (2013)
	p21Rex	tRex
Inihibition of full-length Rex	-	+	Ciminale et al. (1997) Bai et al. (2012)
	p30Tof	p28
Interaction with the co-activator CBP/p300	+	-	Zhang et al. (2001)
	p13	-
Increases mitochondrial K+ permeability and ROS production; inhibits Tax function in the nucleus	+	-	D’Agostino et al. (2005) Silic-Benussi et al. (2009) Andresen et al. (2011) Silic-Benussi et al. (2010b)
	p12	p10
Binding MHC-I heavy chains	+	+	Johnson et al. (2000)
Binding to the IL-2R, calreticulin and calnexin and NFAT activation	+	-	Mulloy et al. (1996) Ding et al. (2001) Ding et al. (2002) Albrecht et al. (2002)
	p8	-
Increases T-cell contacts and intercellular conduits	+	-	Van Prooyen et al. (2010b)
	-	p11	Ciminale et al. (1995)
	Antisense viral proteins
	HBZ	APH-2
Inhibition of Tax-mediated transcription	+++	+	Halin et al. (2009)
p300/CBP interaction	+	-	Clerc et al. (2008)
Transcriptional activity of c-Jun family	-	+	Marban et al. (2012)
Induction of cell proliferation	+	-	Douceron et al. (2012)
Binding to Tax	-	+	Hivin et al. (2005)
bZIP domain	+	-	Marban et al. (2012)