B4GALT1

Protein identityUniProt · HPA

UniProt accession

P15291

Gene

B4GALT1

Ensembl

ENSG00000086062

Chromosome

9

Canonical length

398 aa

Protein class

Disease related genes, Enzymes, Human disease related genes, Metabolic proteins, Plasma proteins, Potential drug targets, Predicted membrane proteins

Subcellular location

Golgi apparatus

Secretome location

Intracellular and membrane

Quaternary structure

Homodimer

OverviewNCBI Gene

This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures. As type II membrane proteins, they have an N-terminal hydrophobic signal sequence that directs the protein to the Golgi apparatus and which then remains uncleaved to function as a transmembrane anchor. By sequence similarity, the beta4GalTs form four groups: beta4GalT1 and beta4GalT2, beta4GalT3 and beta4GalT4, beta4GalT5 and beta4GalT6, and beta4GalT7. This gene is unique among the beta4GalT genes because it encodes an enzyme that participates both in glycoconjugate and lactose biosynthesis. For the first activity, the enzyme adds galactose to N-acetylglucosamine residues that are either monosaccharides or the nonreducing ends of glycoprotein carbohydrate chains. The second activity is restricted to lactating mammary tissues where the enzyme forms a heterodimer with alpha-lactalbumin to catalyze UDP-galactose + D-glucose <=> UDP + lactose. The two enzymatic forms result from alternate transcription initiation sites and post-translational processing. Two transcripts, which differ only at the 5' end, with approximate lengths of 4.1 kb and 3.9 kb encode the same protein. The longer transcript encodes the type II membrane-bound, trans-Golgi resident protein involved in glycoconjugate biosynthesis. The shorter transcript encodes a protein which is cleaved to form the soluble lactose synthase. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

398 residues, UniProt reviewed canonical sequence.

>P15291|B4GALT1
     1  MRLREPLLSG SAAMPGASLQ RACRLLVAVC ALHLGVTLVY YLAGRDLSRL PQLVGVSTPL
    61  QGGSNSAAAI GQSSGELRTG GARPPPPLGA SSQPRPGGDS SPVVDSGPGP ASNLTSVPVP
   121  HTTALSLPAC PEESPLLVGP MLIEFNMPVD LELVAKQNPN VKMGGRYAPR DCVSPHKVAI
   181  IIPFRNRQEH LKYWLYYLHP VLQRQQLDYG IYVINQAGDT IFNRAKLLNV GFQEALKDYD
   241  YTCFVFSDVD LIPMNDHNAY RCFSQPRHIS VAMDKFGFSL PYVQYFGGVS ALSKQQFLTI
   301  NGFPNNYWGW GGEDDDIFNR LVFRGMSISR PNAVVGRCRM IRHSRDKKNE PNPQRFDRIA
   361  HTKETMLSDG LNSLTYQVLD VQRYPLYTQI TVDIGTPS

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against B4GALT1 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability

Cell surface

Secreted

No

Transmembrane segments

1

Mean surface accessibility (rSASA)

0.37

Highest tissue expression

85 nTPM

Expression across tissuesHPA

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about B4GALT1.

Disease | AllUniProt

Conditions B4GALT1 is implicated in, by any mechanism.

• Congenital disorder of glycosylation 2D (CDG2D) MIM:607091
• Combined low LDL and fibrinogen (CLDLFIB) MIM:620364

Disease | GeneticClinVar

3 pathogenic / likely-pathogenic of 155 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

• B4GALT1-congenital disorder of glycosylation
• Combined low LDL and fibrinogen

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)

0.7

gnomAD pLI

0.04

gnomAD missense Z

0.98

DepMap mean gene effect

0.01

DepMap dependency class

selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

• acute inflammatory response
• angiogenesis involved in wound healing
• binding of sperm to zona pellucida
• cell adhesion
• development of secondary sexual characteristics
• epithelial cell development
• epithelial cell proliferation
• extracellular matrix organization
• galactose metabolic process
• lactose biosynthetic process
• lipid metabolic process
• macrophage migration
• negative regulation of epithelial cell proliferation
• oligosaccharide biosynthetic process
• penetration of zona pellucida
• positive regulation of apoptotic process
• positive regulation of epithelial cell proliferation involved in wound healing
• protein N-linked glycosylation
• regulation of acrosome reaction
• positive regulation of circulating fibrinogen levels

Molecular functions

• alpha-tubulin binding
• beta-N-acetylglucosaminylglycopeptide beta-1,4-galactosyltransferase activity
• beta-tubulin binding
• galactosyltransferase activity
• identical protein binding
• lactose synthase activity
• manganese ion binding
• N-acetyllactosamine synthase activity
• UDP-galactosyltransferase activity

Cellular components

• azurophil granule membrane
• basolateral plasma membrane
• brush border membrane
• desmosome
• external side of plasma membrane
• extracellular exosome
• extracellular space
• filopodium
• Golgi apparatus
• Golgi cisterna membrane
• Golgi membrane
• Golgi trans cisterna
• membrane
• plasma membrane
• protein-containing complex
• secretory granule membrane

Protein domainsUniProt · Pfam · InterPro

• Beta-1,4-galactosyltransferase
• Galactosyltransferase, C-terminal
• Galactosyltransferase, N-terminal
• Nucleotide-diphospho-sugar transferases
• N-terminal domain of galactosyltransferase
• N-terminal region of glycosyl transferase group 7

KeywordsUniProt

• Alternative initiation
• Cell membrane
• Cell projection
• Congenital disorder of glycosylation
• Disulfide bond
• Glycoprotein
• Glycosyltransferase
• Golgi apparatus
• Lipid metabolism
• Manganese
• Membrane
• Metal-binding
• Secreted
• Signal-anchor
• Transferase
• Transmembrane
• Transmembrane helix