SEC31A

The protein encoded by this gene shares similarity with the yeast Sec31 protein, and is a component of the outer layer of the coat protein complex II (COPII). The encoded protein is involved in vesicle budding from the endoplasmic reticulum (ER) and contains multiple WD repeats near the N-terminus and a proline-rich region in the C-terminal half. It associates with the protein encoded by the SEC13 homolog, nuclear pore and COPII coat complex component (SEC13), and is required for ER-Golgi transport. Monoubiquitylation of this protein by CUL3-KLHL12 was found to regulate the size of COPII coats to accommodate unusually shaped cargo. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Dec 2015]

SEC31 Homolog A, COPII Coat Complex Component

Component of the coat protein complex II (COPII) which promotes the formation of transport vesicles from the endoplasmic reticulum (ER) (PubMed:10788476).
The coat has two main functions, the physical deformation of the endoplasmic reticulum membrane into vesicles and the selection of cargo molecules (By similarity).

Biological Process COPII-coated vesicle cargo loadingManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process endoplasmic reticulum organizationManual Assertion Based On ExperimentIBA:GO_Central
Biological Process endoplasmic reticulum to Golgi vesicle-mediated transport1 PublicationNAS:UniProtKB
Biological Process intracellular protein transportManual Assertion Based On ExperimentIBA:GO_Central
Biological Process response to calcium ionManual Assertion Based On ExperimentIDA:UniProtKB

Cytoplasm
Cytoplasmic vesicle, COPII-coated vesicle membrane
Endoplasmic reticulum membrane
Cytoplasm, cytosol
Associates with membranes in a GTP-dependent manner (By similarity).
Localizes to endoplasmic reticulum exit sites (ERES), also known as transitional endoplasmic reticulum (tER) (PubMed:25201882, PubMed:28442536, PubMed:17428803).

Neurodevelopmental disorder with spastic quadriplegia, optic atrophy, seizures, and structural brain anomalies (NEDSOSB):
An autosomal recessive, congenital neurodevelopmental disorder characterized by intrauterine growth retardation, microcephaly, marked developmental delay, spastic quadriplegia with profound contractures, pseudobulbar palsy with recurrent aspirations, epilepsy, dysmorphism, neurosensory deafness, optic nerve atrophy with no eye fixation, and death in early childhood. Brain imaging shows semilobar holoprosencephaly and agenesis of corpus callosum.

An autosomal recessive, congenital neurodevelopmental disorder characterized by intrauterine growth retardation, microcephaly, marked developmental delay, spastic quadriplegia with profound contractures, pseudobulbar palsy with recurrent aspirations, epilepsy, dysmorphism, neurosensory deafness, optic nerve atrophy with no eye fixation, and death in early childhood. Brain imaging shows semilobar holoprosencephaly and agenesis of corpus callosum.