TCDB is operated by the Saier Lab Bioinformatics Group
TCIDNameDomainKingdom/PhylumProtein(s)
*1.A.79.1.1









The dsRNA transporter, SID-1 (Systematic RNA interference defective-1).  Forms a gated transmembrane channel (Shih and Hunter 2011; Xu et al. 2013).  May function together with or be regulated by Sid-2, a metal-dependent nucleic acid binding protein (Q9GZC9) (McEwan et al. 2012), Sid-3, a tyrosyl protein kinase (Q10925), named Cdc-42-associated kinase, Ack, in mammals (Jose et al. 2012) and Sid-5 (Q19443) which co-localizes with RAB-7 (Q23146) anXu et al. 2013).  May function together with or be regulated by Sid-2, a metal-dependent nucleic acid binding protein (Q9GZC9) (McEwan et al. 2012), Sid-3, a tyrosyl protein kinase (Q10925), named Cdc-42-associated kinase, Ack, in mammals (Jose et al. 2012) and Sid-5 (Q19443) which co-localizes with RAB-7 (Q23146) and RLP-1 (Q11117).  Endocytosis may play a role in dsRNA uptake.

Eukaryota
Metazoa
SID-1 of Caenorhabditis elegans (AAF98593)
*1.A.79.1.2









The human SID1 protein (Duxbury et al. 2005; Pratt et al. 2012). This protein as well as SidT2 may be cholesterol transporters (Méndez-Acevedo et al. 2017), although they are annotated as RNA transporters, in accordance with several earlier publications.  SIDT1 localizes to endolysosomes and mediates double-stranded RNA transport into the cytoplasm (Nguyen et al. 2019).

Eukaryota
Metazoa
SID1 of Homo sapiens (Q9NXL6)
*1.A.79.1.3









Lysosomal systemic RNA interference defective protein-2, SidT2 of 832 aas and 12 TMSs. It increases the uptake of exogenous dsRNA and DNA (Aizawa et al. 2016).  RNA and DNA are directly taken up by lysosomes in an ATP-dependent manner and degraded. SIDT2 has been reported to mediate RNA translocation during RNA autophagy and DNA translocation during DNA autophagy. Knockdown of Sidt2 inhibited, up to ~50%, total RNA degradation at the cellular level, independently of macroautophagy (Aizawa et al. 2016).  RNA autophagy plays a role in constitutive cellular RNA degradation. SIDT2 also takes up single stranded oligonucleotides into cells (Takahashi et al. 2017). Contu et al. 2017 showed that three cytosolic YXXPhi motifs in SIDT2 are required for the lysosomal localization of SIDT2, and that SIDT2 interacts with adaptor protein complexes AP-1 and AP-2.  On the other hand, Méndez-Acevedo et al. 2017 reported that this protein and SIDT1 transport cholesterol and not RNA. 

Eukaryota
Metazoa
SidT2 of Homo sapiens (Q8NBJ9)
*1.A.79.1.4









SidT2 dsRNA uptake channel

Eukaryota
Metazoa
SidT2 of Siniperca chuatsi
*1.A.79.1.5









The Cholesterol Uptake Protein ChUP-1 of 756 aas and 12 or 13 TMSs (Valdes et al., 2012).

Eukaryota
Metazoa
ChUP-1 of Caenorhabditis elegans (Q9GYF0)
*1.A.79.1.6









The ChUP-1 homologue, Sid1

Eukaryota
Dictyosteliida
ChUP-1 homologue of Dictyostelium discoideum (B0G177)
*1.A.79.1.7









Insect Sid-1 of 766 aas (Xu and Han 2008).

Eukaryota
Metazoa
Sid-1 of Aphis gossypii
*1.A.79.1.8









Sid-1 homologue of 718 aas

Eukaryota
Metazoa
Sid-1 homologue of Caenorhabditis elegans
*1.A.79.1.9









Systemic RNA interference deficient-1 (Sid-1) transmembrane channel for the uptake of dsRNA, involving Sid-1-like proteins A and C, SilA and SilC (Cappelle et al. 2016).

Eukaryota
Metazoa
SilA/C of Leptinotarsa decemlineata (Colorado potato beetle) (Doryphora decemlineata)
*1.A.79.2.1









Prokaryotic Sid-1 homologue of 258 aas

Bacteria
Proteobacteria
Sid-1 homologue of Nitrosococcus watsoni