Gene Symbol: GRAMD1A
Path: /genes/gramd1a
Also Known As: GRAMD1,GRAM-D1, KIAA0272 [@cholesterol2018]
Overview
GRAMD1A (GRAM Domain Containing 1A) is a lipid-binding protein involved in endoplasmic reticulum (ER) function and lipid droplet biology. Formerly known as KIAA0272, this protein plays important roles in cellular lipid homeostasis, membrane trafficking, and has been implicated in various physiological and pathological processes including neurodegeneration. [@stress2017]
Gene Symbol: GRAMD1A
Path: /genes/gramd1a
Also Known As: GRAMD1,GRAM-D1, KIAA0272 [@cholesterol2018]
Overview
GRAMD1A (GRAM Domain Containing 1A) is a lipid-binding protein involved in endoplasmic reticulum (ER) function and lipid droplet biology. Formerly known as KIAA0272, this protein plays important roles in cellular lipid homeostasis, membrane trafficking, and has been implicated in various physiological and pathological processes including neurodegeneration. [@stress2017]
Gene Information
Official Name: GRAM Domain Containing 1A
Gene Symbol: GRAMD1A
Chromosomal Location: 19q13.43
Entrez Gene ID: 8395
Ensembl ID: ENSG00000033122
UniProt ID: Q9BY67
Protein Information
Protein Name: GRAM Domain Containing 1A
Molecular Weight: ~59 kDa
Length: 526 amino acids
Structure: Contains GRAM domain (glucosyltransferases, Rab-like GTPase activators, and myotubularins), StAR-related lipid transfer (START) domain
GRAMD1A functions as a lipid-binding protein with several key roles: [@gramd2016]
Lipid Droplet Formation: Facilitates lipid droplet accumulation and organization. GRAMD1A can bridge the ER membrane to lipid droplets, facilitating lipid transfer.
Cholesterol Metabolism: Binds cholesterol and other lipids through its START domain, participating in cellular cholesterol homeostasis
ER Function: Localizes to ER membranes and participates in ER-related lipid processes
Membrane Trafficking: Involved in intracellular membrane dynamics and lipid transport
The protein contains a GRAM domain that mediates protein-lipid interactions and a START domain that binds cholesterol and oxysterols. GRAMD1A can sense cholesterol levels in cellular membranes and may function as a cholesterol sensor. [@brain2020]
Role in the Nervous System
GRAMD1A is expressed in brain tissue and has several connections to nervous system function: [@lipid2018]
Neuronal Lipid Metabolism: Participates in lipid homeostasis in [neurons](/entities/neurons), which is critical for membrane composition, synaptic function, and neuronal health
ER Stress Response: Modulates ER stress responses, which are particularly important in neurons due to their high metabolic demands
Myelin Formation: May play roles in oligodendrocyte function and myelin maintenance
Synaptic Function: Lipid metabolism is essential for synaptic vesicle formation and neurotransmitter release
Role in Neurodegeneration
GRAMD1A has emerging connections to neurodegenerative diseases: [@neuronal2019]
Alzheimer's Disease
Lipid metabolism dysfunction is a feature of AD brain
GRAMD1A may participate in cholesterol metabolism alterations observed in AD
ER stress is a known contributor to AD pathogenesis, and GRAMD1A modulates ER stress pathways
May influence [amyloid-beta](/proteins/amyloid-beta) metabolism through lipid-dependent mechanisms
Parkinson's Disease
Lipid dysregulation is implicated in PD pathogenesis
GRAMD1A may affect dopaminergic neuron survival through lipid homeostasis
The protein's role in ER function could be relevant to PD-related ER stress
Other Neurodegenerative Conditions
Abnormal lipid metabolism is observed in various neurodegenerative diseases
GRAMD1A may contribute to membrane lipid alterations in these conditions
Lipid Dysregulation in Neurodegeneration
Proper lipid metabolism is essential for neuronal health. GRAMD1A contributes to understanding neurodegeneration through several mechanisms: [@parkinsons2021]
Cholesterol Homeostasis: [Brain cholesterol metabolism](/entities/brain-cholesterol-metabolism) is crucial for neuronal function. Alterations are seen in AD, PD, and other conditions.
Lipid Droplet Dynamics: Neuronal lipid droplets can accumulate under stress, and GRAMD1A regulates their formation.
ER-Mitochondria Lipid Transfer: Proper lipid exchange between organelles is essential for neuronal survival.
Membrane Composition: Synaptic membranes require precise lipid composition for function.