2026-09-30 — initial review (claude-code)
Identity
- UniProt Q4W5P6; 63 aa; single predicted TM helix (res 9-29). UniProt CAUTION: formerly
TMEM155, a 130-residue ORF now considered the wrong CDS; an upstream ORF encodes the
63-aa product. Mouse ortholog: Gm11549 / Nemep (A0A286YD83).
- The human 63-aa product was experimentally shown to be translated
PMID:35810171.
Literature search
- PubMed E-utilities query
NEMEP OR SMIM43 OR TMEM155 OR Gm11549 -> 4 hits. Only
PMID:35810171 (Fu et al. 2022 Nat Commun) is functional. Others are transcriptomic
biomarker lists naming TMEM155 (PMID:41548166 Sjogren/MALT/thyroid; PMID:37077524
acute HIV PBMC upregulation) or unrelated (PMID:28835756). Not cited in the review.
Note: the user's brief said "Fu et al. 2020"; the actual paper is 2022 (PMID:35810171,
verified by title/DOI in PubMed record).
Key findings (Fu et al. 2022, PMID:35810171; full text cached)
Mostly MOUSE (mESC / embryoid body) data:
- Nodal target, required for mesendoderm differentiation of mESCs
PMID:35810171.
- Plasma membrane (mouse, tagged overexpression)
PMID:35810171.
- Binds GLUT1/GLUT3; HUMAN proteins tested in HEK293T co-IP (basis of human IPI rows)
PMID:35810171.
- TMD and H51-F57 required for binding
PMID:35810171.
- KO reduces glucose uptake, rescued by NEMEP
PMID:35810171.
- Binding-deficient mutants fail to boost uptake in GLUT1/3-overexpressing cells; authors hedge
PMID:35810171.
- HUMAN functional data: only overexpression of hNEMEP in HepG2
PMID:35810171.
Mouse GOA (A0A286YD83) for comparison
IDA plasma membrane, IMP GO:0010828 and GO:0048382, IPI GLUT binding — all PMID:35810171.
Human IEA/ISS rows are projections from these.
Decisions
- Plasma membrane: ACCEPT (both rows).
- Transmembrane transporter binding (IPI x2, human proteins): ACCEPT; IEA ACCEPT.
- GO:0010828: MODIFY -> GO:0046326 positive regulation of D-glucose import across plasma
membrane (uptake of glucose/2-DG into cells is what was measured).
- Mesendoderm development: KEEP_AS_NON_CORE. Mouse-only necessity evidence; NEMEP acts by
supplying glucose uptake (metabolic support), not as a developmental regulator per se.
Not tested in human cells.
- NEW MF GO:0141109 transporter activator activity: proposed. Binds GLUT1/3 and increases
their transport activity in a binding-dependent manner. Comparator (QuickGO, 2026-09-30): the SERCA-regulating
microproteins carry regulator-type MFs on their pump partner: DWORF P0DN84 GO:0008047
enzyme activator activity (ISS); SLN O00631 and PLN P26678 GO:0004857 enzyme inhibitor
activity (ISS). For a non-enzymatic transporter partner the analogous term is GO:0141109.
Caveat: authors say "likely"; no reconstituted/proteoliposome assay.