Atypical SLCs
Atypical Solute Carrier Families (Atypical SLCs) are novel plausible secondary active or facilitative transporter proteins that share ancestral background with the known solute carrier families (SLCs). However, they have not been assigned a name according to the SLC root system, or been classified into any of the existing SLC families.[1][2]
Atypical major facilitator superfamily transport families
Most atypical SLCs are families within the major facilitator superfamily (MFS).[3] These atypical SLCs are plausible secondary active or facilitative transporter proteins that share ancestry with the known solute carriers.[1][2][4] They are, however, not named according to the SLC root system, or classified into any of the existing SLC families.[1] ATMFs are categorised based on their sequence similarity and phylogenetic closeness.[3]
| AMTF | Family members | SLC family |
|---|---|---|
| AMTF1 | MFSD9, MFSD10, MFSD14A, MFSD14B | SLC46 |
| AMTF2 | MFSD8 | |
| AMTF3 | MFSD4A, MFSD4B | |
| AMTF4 | CLN3 | |
| AMTF5 | MFSD7 | SLC49 |
| AMTF6 | MFSD1, MFSD5 | |
| AMTF7 | MFSD12 | |
| AMTF8 | MFSD2A, MFSD2B | |
| AMTF9 | SV2A, SV2B, SV2C, SVOP, SVOPL | SLC22 |
| AMTF10 | MFSD11, UNC93A, UNC93B1 | |
| AMTF11 | SPNS1, SPNS2, SPNS3 | |
| AMTF12 | MFSD13A | |
| AMTF13 | MFSD6 | |
| AMTF14 | MFSD6L | |
| AMTF15 | MFSD3 |
Some Atypical SLC of MFS type are: OCA2, CLN3, SPNS1, SPNS2, SPNS3, SV2A, SV2B, SV2C, SVOP, SVOPL, MFSD1, MFSD2A, MFSD2B, MFSD3, MFSD4A,[5] MFSD4B, MFSD5, MFSD6, MFSD6L, MFSD8, MFSD9,[5] MFSD10, MFSD11, MFSD12, MFSD13A, MFSD14A, MFSD14B, UNC93A[6] and UNC93B1. All these are atypical SLCs found within the Major facilitator superfamily. Also TMEM104 (APC clan), OCA2 (IT clan) and CLN3 (having no clan) are atypical SLCs in humans. [7][8][9]
Non-MFS transport families
Although most atypical SLCs are from the major facilitator superfamily, there are exceptions: TMEM104 (APC superfamily), OCA2 (IT superfamily) and CLN3 (unknown superfamily).[1]
References
- ^ a b c d Perland E, Fredriksson R (March 2017). "Classification Systems of Secondary Active Transporters". Trends in Pharmacological Sciences. 38 (3): 305–315. doi:10.1016/j.tips.2016.11.008. PMID 27939446.
- ^ a b Sreedharan S, Stephansson O, Schiöth HB, Fredriksson R (June 2011). "Long evolutionary conservation and considerable tissue specificity of several atypical solute carrier transporters". Gene. 478 (1–2): 11–18. doi:10.1016/j.gene.2010.10.011. PMID 21044875.
- ^ a b Perland E, Bagchi S, Klaesson A, Fredriksson R (September 2017). "Characteristics of 29 novel atypical solute carriers of major facilitator superfamily type: evolutionary conservation, predicted structure and neuronal co-expression". Open Biology. 7 (9): 170142. doi:10.1098/rsob.170142. PMC 5627054. PMID 28878041.
- ^ Höglund PJ, Nordström KJ, Schiöth HB, Fredriksson R (April 2011). "The solute carrier families have a remarkably long evolutionary history with the majority of the human families present before divergence of Bilaterian species". Molecular Biology and Evolution. 28 (4): 1531–1541. doi:10.1093/molbev/msq350. PMC 3058773. PMID 21186191.
- ^ a b Perland E, Hellsten SV, Schweizer N, Arapi V, Rezayee F, Bushra M, Fredriksson R (2017). "Structural prediction of two novel human atypical SLC transporters, MFSD4A and MFSD9, and their neuroanatomical distribution in mice". PLOS ONE. 12 (10): e0186325. Bibcode:2017PLoSO..1286325P. doi:10.1371/journal.pone.0186325. PMC 5648162. PMID 29049335.
- ^ Ceder MM, Lekholm E, Hellsten SV, Perland E, Fredriksson R (2017). "The Neuronal and Peripheral Expressed Membrane-Bound UNC93A Respond to Nutrient Availability in Mice". Frontiers in Molecular Neuroscience. 10: 351. doi:10.3389/fnmol.2017.00351. PMC 5671512. PMID 29163028.
- ^ "TMEM104 transmembrane protein 104 [Homo sapiens (human)] - Gene - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2022-03-14.
- ^ "OCA2 OCA2 melanosomal transmembrane protein [Homo sapiens (human)] - Gene - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2022-03-14.
- ^ "CLN3 CLN3 lysosomal/endosomal transmembrane protein, battenin [Homo sapiens (human)] - Gene - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2022-03-14.