RAB27

RAB27A, member RAS oncogene family
Identifiers
Symbol	RAB27A
NCBI gene	5873
HGNC	9766
OMIM	603868
RefSeq	NM_004580
UniProt	P51159
Other data
Locus	Chr. 15q21
Search for Structures Swiss-model Domains InterPro

RAB27B, member RAS oncogene family
Identifiers
Symbol	RAB27B
NCBI gene	5874
HGNC	9767
OMIM	603869
RefSeq	NM_004163
UniProt	O00194
Other data
Locus	Chr. 18q21.2
Search for Structures Swiss-model Domains InterPro

Rab27is a member of theRabsubfamily ofGTPases.Rab27 is post translationally modified by the addition of twogeranylgeranyl groupson the two C-terminalcysteines.

Pathology

Mutations that prevent the expression of Rab27 ('knock out' mutations) cause the hypopigmentation and immunodeficiency disorder known as type IIGriscelli syndrome,while a decrease in Rab27 prenylation is thought to be involved inchoroideremia.

The symptoms of type IIGriscelli syndromehave shown that Rab27 is involved inmelanosometransport inmelanocytesand in cytotoxic killing activity in cytotoxic Tlymphoblasts.In melanocytes Rab27 binds the melanosome. The melanosome is transported along themicrotubule.Rab27 then recruitsSlac2AandmyosinVa, these enzymes are essential for the transfer of the melanosomes from the microtubules toactinfilaments. The melanosomes can now continue on their path towards the cell periphery. If either Rab27, Slac2A or myosin Va are absent then the melanosomes remain in the perinuclear region of the cell. This disruption in pigmentation results in the hypopigmentation seen in the silvery hair colour of patients withGriscelli syndrome.

External links

• RAB27A+protein,+humanat the U.S. National Library of MedicineMedical Subject Headings(MeSH)
• RAB27B+protein,+humanat the U.S. National Library of MedicineMedical Subject Headings(MeSH)