Reviewed, UniProtKB/Swiss-Prot Q9UQ53 (MGT4B_HUMAN)

Names and origin

Protein names

Recommended name:
    Alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase B
    EC=2.4.1.145
Alternative name(s):
    UDP-N-acetylglucosamine: alpha-1,3-D-mannoside beta-1,4-N-acetylglucosaminyltransferase IVb
    N-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase IVb
      Short name=N-acetylglucosaminyltransferase IVb
      Short name=GlcNAc-T IVb
      Short name=GnT-IVb

Gene names

Name:	MGAT4B
ORF Names:	UNQ906/PRO1927

Organism

Homo sapiens (Human)

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Mammalia › Eutheria › Euarchontoglires › Primates › Haplorrhini › Catarrhini › Hominidae › Homo

Protein attributes

Sequence length	548 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Glycosyltransferase that participates in the transfer of N-acetylglucosamine (GlcNAc) to the core mannose residues of N-linked glycans. Catalyzes the formation of the GlcNAcbeta1-4 branch on the GlcNAcbeta1-2Manalpha1-3 arm of the core structure of N-linked glycans. Essential for the production of tri- and tetra-antennary N-linked sugar chains. Has lower affinities for donors or acceptors than MGAT4A, suggesting that, under physiological conditions, it is not the main contributor in N-glycan biosynthesis.
Catalytic activity	UDP-N-acetyl-D-glucosamine + 3-(2-(N-acetyl-beta-D-glucosaminyl)-alpha-D-mannosyl)-beta-D-mannosyl-R = UDP + 3-(2,4-bis(N-acetyl-beta-D-glucosaminyl)-alpha-D-mannosyl)-beta-D-mannosyl-R. Ref.6
Cofactor	Divalent metal cations By similarity.
Pathway	Protein modification; protein glycosylation.
Subcellular location	Golgi apparatus membrane; Single-pass type II membrane protein By similarity.
Tissue specificity	Widely expressed. Ref.1
Miscellaneous	Strongly overexpressed in pancreatic cancer.
Sequence similarities	Belongs to the glycosyltransferase 54 family.
biophysicochemical properties	Kinetic parameters: KM=0.242 mM for UDP-GlcNAc

Ontologies

Keywords
Cellular component	Golgi apparatus Membrane
Coding sequence diversity	Alternative splicing Polymorphism
Domain	Coiled coil Signal-anchor Transmembrane
Ligand	Metal-binding
Molecular function	Glycosyltransferase Transferase
PTM	Glycoprotein
Gene Ontology (GO)
Biological process	N-glycan processing Ref.1 Traceable author statement. Source: ProtInc
Cellular component	Golgi membrane Inferred from electronic annotation. Source: UniProtKB-SubCell integral to membrane Inferred from electronic annotation. Source: UniProtKB-KW
Molecular function	alpha-1,3-mannosylglycoprotein 4-beta-N-acetylglucosaminyltransferase activity Ref.1 Traceable author statement. Source: ProtInc metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Alternative products

This entry describes 2 isoforms produced by alternative splicing. [Align] [Select]

Isoform 1 (identifier: Q9UQ53-1)

This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.

Isoform 2 (identifier: Q9UQ53-2)

The sequence of this isoform differs from the canonical sequence as follows:
     348-348: Missing.

Note: No experimental confirmation available.

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 548	548	Alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase B		PRO_0000288593
Regions
	Topological domain	1 – 7	7	Cytoplasmic Potential
	Transmembrane	8 – 28	21	Signal-anchor for type II membrane protein Potential
	Topological domain	29 – 548	520	Lumenal Potential
	Coiled coil	36 – 83	48	Potential
Amino acid modifications
	Glycosylation	87	1	N-linked (GlcNAc...) Potential
	Glycosylation	103	1	N-linked (GlcNAc...) Potential
Natural variations
	Alternative sequence	348	1	Missing in isoform 2.		VSP_025716
	Natural variant	257	1	Q → H: dbSNP rs190631.		VAR_053913
	Natural variant	491	1	L → F: dbSNP rs17854722. Ref.3		VAR_032446

Sequences

	Sequence		Length	Mass (Da)
	Isoform 1 [UniParc]. Last modified May 1, 2000. Version 1. Checksum: 1EFF2E681D683C4D	FASTA	548	63,198
	10 20 30 40 50 60 MRLRNGTFLT LLLFCLCAFL SLSWYAALSG QKGDVVDVYQ REFLALRDRL HAAEQESLKR 70 80 90 100 110 120 SKELNLVLDE IKRAVSERQA LRDGDGNRTW GRLTEDPRLK PWNGSHRHVL HLPTVFHHLP 130 140 150 160 170 180 HLLAKESSLQ PAVRVGQGRT GVSVVMGIPS VRREVHSYLT DTLHSLISEL SPQEKEDSVI 190 200 210 220 230 240 VVLIAETDSQ YTSAVTENIK ALFPTEIHSG LLEVISPSPH FYPDFSRLRE SFGDPKERVR 250 260 270 280 290 300 WRTKQNLDYC FLMMYAQSKG IYYVQLEDDI VAKPNYLSTM KNFALQQPSE DWMILEFSQL 310 320 330 340 350 360 GFIGKMFKSL DLSLIVEFIL MFYRDKPIDW LLDHILWVKV CNPEKDAKHC DRQKANLRIR 370 380 390 400 410 420 FKPSLFQHVG THSSLAGKIQ KLKDKDFGKQ ALRKEHVNPP AEVSTSLKTY QHFTLEKAYL 430 440 450 460 470 480 REDFFWAFTP AAGDFIRFRF FQPLRLERFF FRSGNIEHPE DKLFNTSVEV LPFDNPQSDK 490 500 510 520 530 540 EALQEGRTAT LRYPRSPDGY LQIGSFYKGV AEGEVDPAFG PLEALRLSIQ TDSPVWVILS EIFLKKAD
	Isoform 2. Checksum: 20752291F5255E6C	FASTA	547	63,070
	10 20 30 40 50 60 MRLRNGTFLT LLLFCLCAFL SLSWYAALSG QKGDVVDVYQ REFLALRDRL HAAEQESLKR 70 80 90 100 110 120 SKELNLVLDE IKRAVSERQA LRDGDGNRTW GRLTEDPRLK PWNGSHRHVL HLPTVFHHLP 130 140 150 160 170 180 HLLAKESSLQ PAVRVGQGRT GVSVVMGIPS VRREVHSYLT DTLHSLISEL SPQEKEDSVI 190 200 210 220 230 240 VVLIAETDSQ YTSAVTENIK ALFPTEIHSG LLEVISPSPH FYPDFSRLRE SFGDPKERVR 250 260 270 280 290 300 WRTKQNLDYC FLMMYAQSKG IYYVQLEDDI VAKPNYLSTM KNFALQQPSE DWMILEFSQL 310 320 330 340 350 360 GFIGKMFKSL DLSLIVEFIL MFYRDKPIDW LLDHILWVKV CNPEKDAHCD RQKANLRIRF 370 380 390 400 410 420 KPSLFQHVGT HSSLAGKIQK LKDKDFGKQA LRKEHVNPPA EVSTSLKTYQ HFTLEKAYLR 430 440 450 460 470 480 EDFFWAFTPA AGDFIRFRFF QPLRLERFFF RSGNIEHPED KLFNTSVEVL PFDNPQSDKE 490 500 510 520 530 540 ALQEGRTATL RYPRSPDGYL QIGSFYKGVA EGEVDPAFGP LEALRLSIQT DSPVWVILSE IFLKKAD

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"A novel second isoenzyme of the human UDP-N-acetylglucosamine:alpha1,3-D-mannoside beta1,4-N-acetylglucosaminyltransferase family: cDNA cloning, expression, and chromosomal assignment." Yoshida A., Minowa M.T., Takamatsu S., Hara T., Ikenaga H., Takeuchi M. Glycoconj. J. 15:1115-1123(1998) [PubMed: 10372966] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] (ISOFORM 1), TISSUE SPECIFICITY. Tissue: Lung.
[2]	"The secreted protein discovery initiative (SPDI), a large-scale effort to identify novel human secreted and transmembrane proteins: a bioinformatics assessment." Clark H.F., Gurney A.L., Abaya E., Baker K., Baldwin D.T., Brush J., Chen J., Chow B., Chui C., Crowley C., Currell B., Deuel B., Dowd P., Eaton D., Foster J.S., Grimaldi C., Gu Q., Hass P.E. , Heldens S., Huang A., Kim H.S., Klimowski L., Jin Y., Johnson S., Lee J., Lewis L., Liao D., Mark M.R., Robbie E., Sanchez C., Schoenfeld J., Seshagiri S., Simmons L., Singh J., Smith V., Stinson J., Vagts A., Vandlen R.L., Watanabe C., Wieand D., Woods K., Xie M.-H., Yansura D.G., Yi S., Yu G., Yuan J., Zhang M., Zhang Z., Goddard A.D., Wood W.I., Godowski P.J., Gray A.M. Genome Res. 13:2265-2270(2003) [PubMed: 12975309] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1).
[3]	"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)." The MGC Project Team Genome Res. 14:2121-2127(2004) [PubMed: 15489334] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] (ISOFORM 1), VARIANT PHE-491. Tissue: PNS and Uterus.
[4]	"The full-ORF clone resource of the German cDNA consortium." Bechtel S., Rosenfelder H., Duda A., Schmidt C.P., Ernst U., Wellenreuther R., Mehrle A., Schuster C., Bahr A., Blocker H., Heubner D., Hoerlein A., Michel G., Wedler H., Kohrer K., Ottenwalder B., Poustka A., Wiemann S., Schupp I. BMC Genomics 8:399-399(2007) [PubMed: 17974005] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA] OF 176-548 (ISOFORM 2). Tissue: Melanoma.
[5]	"Aberrant expression of N-acetylglucosaminyltransferase-IVa and IVb (GnT-IVa and b) in pancreatic cancer." Ide Y., Miyoshi E., Nakagawa T., Gu J., Tanemura M., Nishida T., Ito T., Yamamoto H., Kozutsumi Y., Taniguchi N. Biochem. Biophys. Res. Commun. 341:478-482(2006) [PubMed: 16434023] [Abstract] Cited for: OVEREXPRESSION IN PANCREATIC CANCER.
[6]	"Kinetic properties and substrate specificities of two recombinant human N-acetylglucosaminyltransferase-IV isozymes." Oguri S., Yoshida A., Minowa M.T., Takeuchi M. Glycoconj. J. 23:473-480(2006) [PubMed: 17006639] [Abstract] Cited for: ENZYME ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBLGenBankDDBJ	AB000624 mRNA. Translation: BAA83464.1. AY358984 mRNA. Translation: AAQ89343.1. BC009464 mRNA. Translation: AAH09464.2. BC051835 mRNA. Translation: AAH51835.1. AL162067 mRNA. Translation: CAB82404.2.
IPI	IPI00477905. IPI00847221.
PIR	T47170.
RefSeq	NP_055090.1.
UniGene	Hs.567419
3D structure databases
ModBase	Search...
Protein-protein interaction databases
IntAct	Q9UQ53. 1 interaction.
Protein family/group databases
CAZy	GT54. Glycosyltransferase Family 54.
PTM databases
PhosphoSite	Q9UQ53.
Proteomic databases
PRIDE	Q9UQ53.
Genome annotation databases
Ensembl	ENSG00000161013. Homo sapiens. [Contig view]
GeneID	11282.
KEGG	hsa:11282.
Organism-specific databases
GeneCards	GC05M179157.
HGNC	HGNC:7048. MGAT4B.
MIM	604561. gene.
PharmGKB	PA30783.
GenAtlas	Search...
Phylogenomic databases
HOVERGEN	Q9UQ53.
Enzyme and pathway databases
BRENDA	2.4.1.145. 247.
Gene expression databases
ArrayExpress	Q9UQ53.
Bgee	Q9UQ53.
CleanEx	HS_MGAT4B.
Family and domain databases
InterPro	IPR006759. Glyco_transf_54. [Graphical view]
PANTHER	PTHR12062. Glyco_transf_54. 1 hit.
Pfam	PF04666. Glyco_transf_54. 1 hit. [Graphical view]
ProtoNet	Search...
Other Resources
NextBio	42949.
SOURCE	Search...

Entry information

Entry name

MGT4B_HUMAN

Accession

Primary (citable) accession number: Q9UQ53
Secondary accession number(s): Q86TF1, Q96GH4, Q9NSK6

Entry history

Integrated into UniProtKB/Swiss-Prot:	May 29, 2007
Last sequence update:	May 1, 2000
Last modified:	May 5, 2009
This is version 51 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HPI (Human Proteome Initiative)