CG3631

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0004674 protein serine/threonine kinase activity	ISS PMID:22900076 The Raine syndrome protein FAM20C is a Golgi kinase that pho...	REMOVE	Summary: Protein phosphorylation is not established for the FAM20B-like CG3631 branch. Reason: The cited full paper separates CG3631/FAM20B from CG31145/FAM20C and reports casein phosphorylation for CG31145, not CG3631. Structural and biochemical work identifies FAM20B as a glycan xylose kinase. The ISS transfer therefore assigns the substrate class of the other branch; the evidence supports an alcohol-group phosphotransferase inference instead. Supporting Evidence: PMID:22900076 CG3631, which is most closely related to FAM20B PMID:29572475 Fam20B phosphorylates a xylose residue to regulate proteoglycan synthesis.
GO:0005783 endoplasmic reticulum	IDA PMID:22900076 The Raine syndrome protein FAM20C is a Golgi kinase that pho...	ACCEPT	Summary: CG3631 occupies an ER-associated secretory-pathway compartment. Reason: Tagged CG3631 overlaps the ER marker in S2 cells in the cited primary study. This target-specific localization is supported even though other FAM20 members have different distributions. Supporting Evidence: PMID:22900076 CG3631 overlapped both ER and Golgi markers, and was not detectably secreted from S2 cells
GO:0005783 endoplasmic reticulum	IEA GO_REF:0000044	ACCEPT	Summary: CG3631 occupies an ER-associated secretory-pathway compartment. Reason: Tagged CG3631 overlaps the ER marker in S2 cells in the cited primary study. This target-specific localization is supported even though other FAM20 members have different distributions. Supporting Evidence: PMID:22900076 CG3631 overlapped both ER and Golgi markers, and was not detectably secreted from S2 cells
GO:0005794 Golgi apparatus	IDA PMID:22900076 The Raine syndrome protein FAM20C is a Golgi kinase that pho...	ACCEPT	Summary: CG3631 also localizes to the Golgi. Reason: The same target-specific imaging experiment shows overlap with a Golgi marker, so ER and Golgi residence are compatible rather than mutually exclusive annotations. Supporting Evidence: PMID:22900076 CG3631 overlapped both ER and Golgi markers, and was not detectably secreted from S2 cells
GO:0005794 Golgi apparatus	IEA GO_REF:0000044	ACCEPT	Summary: CG3631 also localizes to the Golgi. Reason: The same target-specific imaging experiment shows overlap with a Golgi marker, so ER and Golgi residence are compatible rather than mutually exclusive annotations. Supporting Evidence: PMID:22900076 CG3631 overlapped both ER and Golgi markers, and was not detectably secreted from S2 cells
GO:0016773 phosphotransferase activity, alcohol group as acceptor	IBA GO_REF:0000033	ACCEPT	Summary: Alcohol-group phosphorylation is the appropriate broad activity for the FAM20B branch. Reason: The experimentally established FAM20B substrate is glycan-linked xylose, which carries the phosphorylated hydroxyl group. CG3631 has the FAM20B-like evolutionary placement documented in the primary comparison; the conserved broad chemistry is supported while direct fly substrate assays remain absent. Supporting Evidence: PMID:22900076 CG3631, which is most closely related to FAM20B PMID:29572475 Fam20B phosphorylates a xylose residue to regulate proteoglycan synthesis.
GO:0030166 proteoglycan biosynthetic process	IBA GO_REF:0000033	ACCEPT	Summary: Proteoglycan biosynthesis is consistent with the FAM20B-type glycan kinase. Reason: The PAINT inference fits CG3631 placement next to FAM20B and its ER/Golgi localization. Mammalian FAM20B biochemistry supplies the mechanism of linker-xylose phosphorylation; direct CG3631 glycan assays would refine the target-specific substrate claim. Supporting Evidence: PMID:22900076 CG3631, which is most closely related to FAM20B PMID:29572475 Fam20B phosphorylates a xylose residue to regulate proteoglycan synthesis. PMID:22900076 CG3631 overlapped both ER and Golgi markers, and was not detectably secreted from S2 cells