The reference OMIM entry for this protein is 600862

Adp-ribosylation factor gtpase-activating protein with fg repeats 1; agfg1
Arfgap with fg repeats 1
Hiv-1 rev-binding protein; hrb
Rev-interacting protein; rip
Rev/rex activation domain-binding protein; rab

CLONING

Using the yeast 2-hybrid screening system to identify proteins that interact with the Rev protein of HIV-1 and which thereby assist in HIV replication, Fritz et al. (1995) identified a novel cDNA, which they designated Rev-interacting protein (RIP). A partial clone from the initial screen was used to obtain a full-length 2.4-kb RIP cDNA. The authors found that the predicted 562-amino acid protein is related to the nucleoporins (e.g., 114350), a class of proteins that mediate nucleocytoplasmic transport. The protein was detected in the nuclear extract of HeLa cells and by immunofluorescence on the nuclear surface. Expression studies showed that recombinant RIP did indeed lead to increased Rev activity. Bogerd et al. (1995) also cloned the HRB gene using a yeast 2-hybrid screen to identify proteins that interact with the activation domains of Rev and the equivalent regulatory protein from human T-cell leukemia virus type 1 (HTLV1), Rex. They designated the protein RAB for 'Rev/Rex activation domain-binding protein.' By SDS-PAGE, human, mouse, quail, and frog RAB migrated as an approximately 60-kD protein. The RAB gene was expressed as a major 2.8-kb and a minor 4.6-kb mRNA in all tissues examined.

GENE FUNCTION

Salcini et al. (1997) reported that both the RAB and RABR (604018) proteins bind to the EH protein-protein interaction domain found in EPS15 (600051) and other proteins. Coimmunoprecipitation studies demonstrated that RAB and EPS15 are associated in vivo. Bogerd et al. (1995) showed that RAB binds to the Rev activation domain in vitro and in vivo and also to functionally equivalent domains in Rex and in other Rev proteins from diverse viruses. By ablating RIP activity with a dominant-negative mutant or RNA interference, Sanchez-Velar et al. (2004) analyzed the role of RIP in Rev-directed RNA movement by RNA in situ hybridization. In the absence of functional RIP, Rev-directed RNAs mislocalized and aberrantly accumulated at the nuclear periphery, where RIP is localized. In contrast, in the absence of Rev or a Rev cofactor, Rev-directed RNAs remained nuclear. The RNA mislocalization pattern was specific to viral RNA. The intracellular distribution patterns of cellular mRNA, nuclear proteins, and cellular proteins containing a nuclear export signal were unaffected. Sanchez-Velar et al. (2004) concluded that RIP is a cellular Rev cofactor essential for the nuclear export of viral RNAs.

MAPPING

Jones et al. (1997) used fluorescence in situ hybridization to map the RIP gene to human chromosome 2q36.

ANIMAL MODEL

Kang-Decker et al. (2001) generated mice deficient in HRB by targeted disruption. Male mice with a null mutation in Hrb were infertile and displayed round-headed spermatozoa that lacked an acrosome. In wildtype spermatids, Hrb was associated with the cytosolic surface of proacrosomic transport vesicles that fuse to create a single large acrosomic vesicle at step 3 of spermiogenesis. Although proacrosomic vesicles form in spermatids that lack Hrb, the vesicles are unable to fuse, blocking acrosome development at step 2. Kang-Decker et al. (2001) concluded that HRB is required for docking and/or fusion of proacrosomic vesicles during acrosome biogenesis. ... More on the omim web site

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Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated

Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated

Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated

March 16, 2016: Protein entry updated
Automatic update: OMIM entry 600862 was added.

Jan. 24, 2016: Protein entry updated
Automatic update: model status changed